On November 24th, 2021, NASA launched the Double Asteroid Redirection Test (DART) mission, a vehicle aimed at testing a method of planetary defence against near-Earth objects (NEOs) the pose a real risk of impact.
I’ve covered the risk we face from Earth-crossing NEOs – asteroids and cometary’s fragments that routinely zoom across or graze the Earth’s orbit as they follow their own paths around the Sun. We are currently tracking some 8,000 of these objects to assess the risk of one of them colliding with Earth at some point in the future. This is important, because it is estimated a significant impact can occur roughly every 2,000 years, and we currently don’t have any proven methods of mitigating the threat should it be realised. And that is what DART is all about: demonstrating a potential means of diverting an incoming asteroid threat.
Developed as a joint project between NASA and the Johns Hopkins Applied Physics Laboratory (APL), DART is specifically designed to deflect an asteroid purely through its kinetic energy; or to put it another way, by slamming into it, and without breaking it up. Both are important, because by simply slowing an Earth-crossing NEO along its orbit, we give time for Earth to get out of its way; then, by not causing it to break, then we avoid the risk of it becoming a hail of shotgun pellets striking Earth at some point further into the future.
The target for the mission is a binary asteroid 65803 Didymos (Greek for “twin”), comprising a primary asteroid approximately 780 metres across, and a smaller companion called Dimorphos (Greek: “two forms”) caught in a retrograde orbit around it, with both orbiting the Sun every 2 years 1 month, periodically passing relatively close to Earths, as well as periodically grazing that of Mars.
Discovered in 1996 by the Spacewatch sky survey the pair has been categorised as being potentially hazardous at some point in the future. At some 160m across, Dimorphos is in the broad category of size for many of the Earth-crossing objects we have so far located and are tracking, making it an ideal target.
DART actually started as a dual mission in cooperation with the European Space Agency (ESA) called AIDA – Asteroid Impact & Deflection Assessment. This would have seen ESA launch a mission called AIM in December 2020 to rendezvous with Didymos and enter orbit around it in order to study its composition and that of Dimorphos, and to also be in position to observe DART’s arrival in September 2022 and its impact with the smaller asteroid.
However, AIM was ultimately cancelled, leaving NASA to go ahead with DART. To reduce costs, NASA initially looked to make it a secondary payload launch on a commercial rocket. But it was ultimately decided to use a dedicated Falcon 9 launch vehicle for the mission, allowing it to make its September 2022 rendezvous with Dimorphos.
In order to impact the asteroid at a speed sufficient to affect its velocity, DART needs to be under propulsive power. It therefore uses the NEXT ion thruster, a type of solar electric propulsion that will propel it into Dimorphos at a speed of 6.6 km/s – which it is hoped will change the velocity of the asteroid by 0.4 millimetres a second. This may not sound a lot, but in the case of hitting an actual threat whilst it is far enough away from Earth, it is enough to ensure it misses the planet when it crosses our orbit.
This motor is powered by a deployable solar array system first deployed to the International Space Station (ISS). However, what is most interesting about these solar panels is that a portion of them is configured to demonstrate Transformational Solar Array technology that can produce as much as three times more power than current solar array technology and so could be revolutionary should it reach commercial production.
Accompanying DART is Light Italian CubeSat for Imaging of Asteroids (LICIACube), a cubesat developed by the Italian Space Agency, and which will separate from DART 10 days before impact to acquire images of the impact and ejecta as it drifts past the asteroid. To do this, LICIA Cube will use a pair of cameras dubbed LUKE and LEIA.
As the cubesat is unable to orbit Didymos to continue observations, ESA is developing a follow-up mission called Hera, Comprising a primary vehicle bearing the mission’s name, and two cubesats, Milani and Juventas, this mission will launch in 2024, and arrive at the asteroids in 2027, 5 years after DART’s impact, to complete a detailed assessment of the outcome of that mission.
ISS Gets a New Module
On November 26th, 2021, a new Russian module arrived at the International Space Station (ISS).
The Prichal, or “Pier,” module had been launched by a Soyuz 2.1b rocket out of the Baikonur Cosmodrome in Kazakhstan two days earlier. Mounted on a modified Progress cargo vehicle, the module was successfully mated with the Nauka module which itself only arrived at the station in July, at 15:19 UTC.
The four-tonne spherical module has a total of six docking ports, one of which is used to connect it with Nauka, leaving five for other vehicles. However, when first conceived, the module was also intended to be a node for connecting future Russian modules.
But since that time, the Russian space agency, Roscosmos, has abandoned plans to support the ISS with additional modules. Instead, with relations with the west continuing to cool and the ongoing rise in nationalism in Russia, the agency has indicated it plans to orbit its own space station. This being the case, Prichal is viewed as the final element in the Russian segment of ISS, and potentially the first of the new station.
Unlike the arrival of Nauka in July, Prichal managed to dock with the ISS without the additional “excitement” of any thruster mis-firings. Now, the Progress carrier vehicle will remain attached to the module through until December 21st, allowing time for the Russian cosmonauts on the station to carry out a spacewalk to attach Prichal to the station’s power systems. Once it has been detached, the Progress vehicle will be set on a path to burn-up in the Earth’s atmosphere.
As well as expending the docking facilities at the ISS, Prichal delivered some 2.2 tonnes of cargo and supplies to the station. The module will formally commence operations in its primary role in March 2022 with the arrival Soyuz MS-21.
Anyone who follows news on space activities will be aware that on November 15th, Russia carried out the test of an anti-satellite(ASAT) missile system that resulted in the destruction of a defunct Soviet-era electronic signals intelligence (ELINT) satellite – and required the crew of the International Space Station (ISS) to move to their respective Earth return vehicles (Soyuz MS-19 and Crew Dragon Endurance) due to risk of being hit by the debris.
To be clear, ASAT systems are not new. The United States and Russia (/the Soviet Union) have between them spent decades developing and testing such systems (the last successful US test was in 2006, with both the USAF and USN having significant ASAT capabilities), and China and India have also demonstrated ASAT systems as deliberate demonstrations of force.
However, the November 15th test by Russia was somewhat different. Occupying a polar orbit at an average altitude of around 470 km, the 2.2 tonne Kosmos 1408 as both a substantial target risking a massive debris cloud, and routinely “passed over” the orbit of the ISS (ave 420 km), putting it at clear risk. Nor did Russia give any forewarning of the test.
Instead, the US Space Command only became aware of what had happened after they tracked the missile launch all the way to impact – and then started tracking the cloud of debris. This presented no danger to the ISS in its first orbit, but tracking showed it was a very define threat to the station on its 2nd and 3rd orbits, prompting mission controllers to order the ISS crew to start shutting down non-essential operations and sealing-off hatches between the various science modules.
Some 15 minutes before the second pass of the debris field across the station’s orbit, controllers called the station to order the US / European astronauts in the “US section” of the station to secure all remaining hatches to minimise the risk of explosive decompression in the event of a hit, and evacuate to Crew Dragon Endurance both in case an emergency undock was required, and because it presented a significantly smaller target for any stray debris travelling at 28,000 km. The controllers also noted the Russia cosmonauts on the station were engaged in similar actions, and would be retiring to their Soyuz MS-19 vehicle.
In all, the crews were restricted to their Earth return vehicles for somewhere in the region of 3-3.5 hours before it was considered the most significant risk of and impacts had for the most part passed. Even so, it was not until November 17th that all hatches on the ISS were unsealed to allow normal operations to resume throughout all modules. Currently, NASA is still monitoring the situation and may postpone a spacewalk planned for November 30th as a result of the debris risk.
Ironically, on November 11th, the ISS had to raise its orbit somewhat using the thrust from a docked Progress re-supply vehicle in order to completely remove the risk of debris from 2007 Chinese ASAT weapon test striking it, 14 years after the test.
Following the test, Russia attempted to play down the risk, stating it posed “no threat” to other orbital vehicle, crewed or uncrewed – a less than accurate statement. Analysis of the debris cloud by both US Space Command and civilian debris tracking organisations reveals much of the cloud will remain a threat for the next several years – if not decades – as the convoluted nature of orbital mechanics and impact velocity gradually increases the cloud’s orbital altitude for a time as it continues to disperse, putting satellites in higher orbits at risk – particularly the likes of the SpaceX Starlink and the OneWeb constellations.
Russia has demonstrated a deliberate disregard for the security, safety, stability, and long-term sustainability of the space domain for all nations. The debris created by Russia’s DA-ASAT will continue to pose a threat to activities in outer space for years to come, putting satellites and space missions at risk, as well as forcing more collision avoidance manoeuvres.
– U.S. Army General James Dickinson, Space Command.
Some 1500 individual pieces of debris from the test are of a trackable size, with potentially tens of thousands more that are too small to be identified. Tim Flohrer, head of the European Space Agency’s (ESA) Space Debris Office noted that the test means that debris avoidance manoeuvres made by satellites in the 400-500 km orbit range may increase by as much as 100% for the next couple of years before the threat is sufficiently dissipated. One of the biggest risks posed by this kind of action is the Kessler Effect (or Kessler Syndrome), wherein debris from one impact causes a second impact, generating more debris, and so setting off a chain reaction.
Given its size and orbit, there is simply no way Russia was unaware of the threat posed by Kosmos 1408 to low-orbit vehicles – particularly crewed vehicles and facilities – if the test was successful. As such, some have seen it as irresponsible due to the impact it could have on general orbital space operations, while others see it as a sign of aggressive intent on Vladimir Putin’s part.
Currently, Russia has not indicated as to whether this was a one-off incident (a previous test in 2020 missed its target), as has been the case in the US, Chinese and Indian tests, or if it could be a part of a wide series of tests. If the latter, then international relationships are liable to be further strained.
NASA OIG: No Moon Landing Before 2026
Following NASA’s indication that the first Artemis lunar laying won’t come “earlier” that 2025, the agency’s own Office of Inspector General (OIG) has thrown a bucket of realism over the entire project, pretty much confirming comments made in this blog concerning vehicle development timelines, whilst also questioning the sustainability of the programme.
Having carried out an extensive audit of the programme, OIG has issued a 73-page report which critiques the current Artemis programme and time frames, although it can only offer suggestions on what might be done, not instigated changes.
It terms of the development of the Human Landing System (HLS), required to get crews to / from the surface of the Moon, the report follows what has been noted in Space Sunday: the 4-year development time frame is simply unrealistic. In particular, the report notes that even in partnerships such as the Commercial Crew Programme, NASA tends to require around 8.5 years to develop a new spaceflight capability – more than double that allocated for HLS (in fact, NASA / SpaceX believed Crew Dragon could be developed and ready for operation in 6 years – it took 10). It also indicates that while a reliance on a single vehicle design / contractors (currently SpaceX) reduces costs, it also places further risk on the entire programme time fame and operations.
Further, the OIG report states that realistically, the first flight of the first Space Launch System (SLS) rocket is unlikely to take place until mid-2022; somewhat later than NASA is still projecting (early 2022). It goes on to point of that given the delays on Artemis 1, it is unlikely that the Artemis 2 mission scheduled for 2023 and which will fly a crew around the Moon and back to Earth in a manner akin to Apollo 8 is unlikely to be ready until mid-2024, simply because NASA plan to re-use elements from the Artemis 1 Orion vehicle in the Artemis 2 Orion, and these will need a comprehensive post-flight examination and refurbishment.
Beyond this, the report also raises concerns whether the space suit required for lunar operations – the Exploration Extravehicular Mobility Unit (xEMU) – will actually be ready for operations in 2025, issues in technical development, and in NASA flip-flopping between in-house and commercial contract development of the suit being pointed to as reasons for the delays.
The biggest critique in the report, however, is related to costs. The OIG report notes that at current levels of expenditure, Artemis will cost US $93 billion by 2025/26, with the first four Artemis SLS / Orion launches (Artemis 1 through 4) alone costing US $4.1 each – and this estimate does not include the development of the actual HLS system or the costs to launch / operate it.
To reduce these costs, OIG suggests looking to alternate launch vehicles to deliver crews to lunar orbit, but NASA management has already rejected such ideas and had refuted OIG’s cost analysis and call for most closely accounting for expenditure. However, it has accepted the report’s other concerns; although it will take time to see if this translates into any form of re-assessment of the programme as a whole.
Up until now, the only means to get payload into space has been through chemical propulsion – rockets. And while they are not entirely efficient, they do work. However, if an American company gets its way, launching small payload into orbit could see the core part of their rocket replaced by a vacuum accelerator. Think of whirling an object around at speed on the end of a piece of string and then releasing it vertically, and you’ll get the picture.
The idea may sound bonkers, but it is precisely what US company SpinLaunch is planning to do.
They propose building a 100-metre diameter vacuum accelerator that, over the course of 90 minutes can accelerate an 11.2 tonne launch system up to a speed of Mach 5 before releasing it to travel along a launch tube and into the air. This velocity should be sufficient to propel the launch vehicle – comprising an aerodynamic aeroshell within which is placed a two-stage rocket carrying a 200 Kg payload.
On reaching a altitude matching that of a Falcon 9 first stage, the aeroshell would then split open, releasing the rocket to power itself and its payload on to orbit. Sound this work, it could reduce the cost of placing small payloads into space by around 80%, and allow for multiple launches from a single facility per day, if required.
To prove the idea works, SpinLaunch has constructed a one-third scale version of the accelerator, and on October 22nd, used it – operating at around 20% of rated output – to propel a 3-metre long ballistic projectile “tens of thousand of feet” into the atmosphere. According to SpinLaunch, the test was the first of 30 to take place over the next 6 months before they start work on construction on what they claim will be the first of a number of full-scale launch facilities at various points on the American coast.
That said, there are some significant technical challenges. Spinning at a maximum speed of 450 rpm, the system will subject the launcher and its payload to a peak dynamic load of 10,000 G; that’s a lot for the more sensitive part of the rocket motor to handle. More particularly, when it breaks the vacuum seal at the end of the launch tube, it will be travelling at Mach 5 – and slamming straight into the densest part of the atmosphere, again placing a massive load on it and its payload, as well as generating a lot of frictional heat as a result of its passage through the air. And that’s without considering the challenges in translating the spin of the accelerator into linear motion for the launch vehicle such that it can smoothly and successfully exit the launch tube, etc.
Even so, SpinLaunch appear to be carrying out the right amount of research – even if they are somewhat circumspect in addressing specific technical questions. As such, it will be interesting to see where things lead.
SpaceX Starship Update
With the public phase of the FAA’s Programmatic Environmental Assessment (PEA) of the Starbase facilities at Boca Chica now closed and the agency putting together its final version of the report, SpaceX has been moving ahead with site and vehicle development.
Most notably with the former has been work on erecting the framework of the new Wide Bay facility that could allow work to progress on up to four Super Heavy / Starship vehicles at a time, massively increasing the ability for the company to stack vehicles elements together. At the same time, in the current 2-vehicle High Bay, Booster 5 is nearing stack completion, and work has resumed on Starship 21.
Booster 5 includes significant differences to Booster 4, which is now sitting on a hard stand at the launch facilities as work continues on the launch platform there. Most notably, elements of the booster are emerging from the fabrication facilities in a completed state than was the case with Booster 4 – which even now, is still awaiting various elements of aerodynamic casing, etc., to protect various parts during its ascent and decent through the atmosphere. Similarly, Starship 21 is showing differences in construction to Starship 20, most notably in having sections fitted with their thermal protection blankets and tiles prior to being stacked together.
At the launch site, work has continued in getting the catching mechanism on the launch support tower properly rigged to the cable system and massive winches that will allow it to move up and down the tower for eventual stacking and catching operations. A short distance away, Booster 4 has started to receive the protective skirting around its base to keep the more sensitive parts of its ring of outer engines safe from the flames and heat of ignition, as well receiving the last of its 29 Raptor engines.
However, the biggest new in recent weeks came with the pre-burn and static fire test of all six Raptor motors on Starship 20. These came almost back-to-back on November 12th, with the pre-burn (a kind of clearing the rocket engines’ throats) coming first and lasting just under a second. Then, around an hour later came a 2-second firing of the vehicles’ 3 sea-level engines and the 3 vacuum rated engines.
As with the last static fire test (with just 3 motors), some of the vehicle’s thermal protection tiles were blown clear, with a good number coming off lower down the vehicle when compared to the 3-engine test. Although brief, the static fire gave a small taste of the amount of noise that will be generated when Booster 4 ignites all 29 of its motors and then sustains their thrust through an actual launch.
Whether or not this launch, which will hopefully carry Starship 20 aloft, will come before the end of the year still hangs in the balance, with a lot riding on the outcome of the FAA’s final version of their PEA.
Hubble Partially Recovered
On October 25th, the Hubble Space Telescope (HST) entered a “safe” mode, shutting down all science operations, the result of “multiple losses of synchronisation messages” – messages designed to coordinate how the various science instruments on HST receive and transmit data to / from the telescope’s primary computer system. While of concern, and possibly a little more frequent than initially diagnosed, the issue left Hubble in good health and engineers confident science operations could be recovered.
During the week, further tests were carried out that gave NASA the confidence to return the Advanced Camera for Surveys (ACS) to operational status on November 7th. The coming week will see the completion of additional tests with the hope that the more sensitive instruments on the telescope can be returned to operational status.
Artemis 3 Moon Landing Now “No Earlier” Than 2025
In a move that should have surprised no-one interested in space exploration, NASA has pushed back their return to the Moon to at least 2025, citing four reasons: the disagreement with Blue Origin over the contract for the Human Landing System (HLS), delays due to COVID working restrictions in 2020, Congress “failing” to fund HLS development and the Trump Administration placing unrealistic time frames on the programme.
Of the four reasons, the last is perhaps the most accurate: you simply cannot lop 4 years off of a programme and expect it to succeed (simply so you can take the credit as theoretically still be in office), without a commensurate increase in budget to allow NASA to achieve the required goals in the reduced time frame. On the other hand, blaming Congress isn’t entirely honest. In 2019, NASA stated they need $5+ billion for HLS development – but only requested less than $2 billion – hoping they could take money from the infrastructure bill and put into HLS – which Congress refused to allow.
As it is, the “no earlier” statement is standard NASA parlance when they do not wish to commit to a specific data as yet, in this instance it is perhaps indicative that Artemis 3 could slip to 2026. A lot is riding on the Artemis 1 mission, which has already slipped to February 2022, being the first flight of the Space Launch System (SLS) rocket critical in getting crews to the Moon. Should this first (uncrewed) flight reveal issues with either SLS or the Orion crew vehicle, then it is likely to seriously impact the entire Artemis timeline.
Similarly, while Elon Musk claims SpaceX will be able to land a crewed Starship HLS vehicle on the Moon in 2023, his time-frames tend to be over-optimistic. Also, there are some major questions around the Starship HLS that have yet to be answered; plus SpaceX are working to NASA’s crew safety requirements, not their own, which can (rightly, given crew safety is at stake) cause additional overheads on a development programme.
Crew Dragon: 4 Down, 4 Up
After uncooperative weather mixed things up, and caused delays, SpaceX Crew Dragon Endeavour has returned to Earth, bringing with it NASA astronauts Shane Kimbrough and Megan McArthur, ESA astronaut Thomas Pesquet and JAXA astronaut Aki Hoshide, who were all just a few hours short of spending 200 days aboard the space station.
Departure and splashdown took place on November 8th, with only the late-opening of one of the 4 main parachutes preventing the return from being perfectly textbook.
The departure left a lone US astronaut on the ISS along with two Russian cosmonauts. Mark Vende Hei arrived on the station aboard Soyuz MS-18 in April 2021. In September he and cosmonaut Pyotr Dubrov, who also flew to the station on MS-18, had their stay on the station extended through until March 2022. This means that Vende Hei will take the record for the longest individual space flight by an American – 353 days.
However, on Thursday, November 11th, he was joined by NASA colleagues Raja Chari, Tom Marshburn, and Kayla Barron, who arrived at the ISS along with ESA astronaut Matthias Maurer aboard Crew Dragon Endurance as the Crew 3 mission. They had launched earlier on Thursday, November 11th (Late on Wednesday, November 10th, US time), marking the maiden flight of the third Crew Dragon vehicle to enter service. They will remain aboard the station for 6 months.
Further Push to Retire SOFIA
NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA), the 2.5 metre telescope flown aboard a converted 747 SP aircraft has been recommended for “termination” by the committee that originally prioritised it.
The astrophysics decadal survey committee, which originally pushed for the airborne observatory in both 1990 (when it was not funded) and 2000 (when it was, although technical issues meant it did not enter service until 2014), now believe it is not worth the annual US $85 million cost of operating it and a “lack” of “scientific productivity”.
The “lack of productivity” references the fact that in its first 6 years, SOFIA has only generated 178 scientific papers that were cited 1,242 times, far less than other, more specialised observatories like the Transiting Exoplanet Survey Satellite (TESS); however, supporters of SOFIA note that the figures ignore the fact that in the last 12 months there has been a 59% increase in SOFIA papers, and the observatory is gaining more use in a variety of roles.
NASA has twice tried to cancel SOFIA, but in 2020 Congress provided sufficient funding for operations to through 2021 and into 2022. Currently, the House has also provided funding for the observatory until the end of 2023, although the Senate has yet to make a determination on funding.
Blue Origin Space Tourist Killed
Glen de Vries, who flew with William Shatner, Chris Boshuizen and Audrey Powers, a Blue Origin vice president on the second passenger-carrying Blue Origin New Shepard sub-orbital flight, was one of two people on a Cessna 172 aircraft that crashed in New Jersey on November 11th.
De Vries, a biomedical entrepreneur and self-described “space nerd”, paid an undisclosed sum for the flight, and had been giving talks and presentations on his experience since his return to Earth.
At the time of his death, he had been flying with Thomas Fischer from Essex County Airport in Caldwell, N.J. Both men were well-qualified pilots – Fischer also being a flight instructor – but it is not clear who was flying the aircraft. Emergency services were alerted after the pair failed to arrive at their destination, and the wreckage of the aircraft were subsequently found in a heavily wooded area near Hampton Township, about 64 kilometres northwest of New York City. At the time of writing, the cause of the crash remains undetermined.
We are devastated to hear of the sudden passing of Glen de Vries. He brought so much life and energy to the entire Blue Origin team and to his fellow crewmates. His passion for aviation, his charitable work, and his dedication to his craft will long be revered and admired.
Blue Origin statement on the death of Glen de Vries