Space Sunday: spaceflight briefs

A rendering of the Chinese Tiangong space station as it appeared immediately following the Mengtian science module’s arrival. From left to right: The Mengtian module attached to the axial port of the Tinahe-1 docking hub; Centre: the Wengtian science module attached to the starboard port of the hub. Centre right: the Tianhe-1 core module with the Tianzhou 4 resupply vehicle docked against its after port. Just visible and extending away from the nadir port of the docking hub, centre, is the Shenzhou 14 crew vehicle. Credit: CMSA

China has completed all major construction activities with its Tiangong space station following the arrival of the ~20 tonne Mengtian laboratory module at the station. Launched at 07:37 UTC on Monday, 31st October, 2022, the module arrived at the space station 13 hours later, completing an automated docking with the axial port on the station’s docking hub, the docking overseen by the current crew on three on the station – Chen Dong, Liu Yang and Cai Xuzhe.

Following this, on November 3rd, ground personnel used the docking manipulator on the module to literally grapple itself around to the hub’s portside docking ring. once a hard dock and pressurisation of the inter-module area had been confirmed, the hatches were undogged and the crew entered the module to commence preparing it for operations.

Next up for the station is the flight of the Tianzhou 5 automated resupply vehicle, due to launch on a Long March 7 rocket on November 12th. This will deliver additional supplies to the station ahead of the handover of the station from the Tianzhou 14 crew to the Tianzhou 15 crew, which is due to take place before the end of 2022.

A rendering of Tiangong as it now appears: to the left, and “pointing towards Earth” is the Wengtian science module; Shenzhou 14 can be seen docked at the nadir port on the docking hub, and Mengtian is in the foreground, forming the station’s T-bar with Wengtian. Extending back from the docking hub is the Tianhe-1 core module and the Tianazhou 4 resupply vehicle. Credit: CMSA

This was  not the end of the story for this launch however; on Friday, November 4th, the core stage of the Long March 5B rocket made an uncontrolled re-entry into the atmosphere. As I  noted in my previous Space Sunday update, China has  cavalier attitude towards large parts of its Long March core stages surviving re-entry to potentially fall on a populated area. In this case, the final track of the booster core saw it passing over numerous population centres in southern Europe and the Middle East, including Lisbon in Portugal, Barcelona and Madrid in Spain, Marseille in France, and Rome in Italy. As a result, emergency services were on alert, and an air safety notice was issued, closing EU airspace along the track of booster against the risk of smaller debris striking airliners and cargo aircraft.

Tracked by the US Space Force and EU Space Surveillance and Tracking (EUSST), the booster eventually re-entered the atmosphere over the Pacific Ocean, the remnants falling into the seas there without incident. The re-entry of this vehicle means the core stages of the Long March 5B account for 4 of the six largest objects making uncontrolled re-entries; only the U.S Skylab (1979; ~77 tonnes) and the Soviet Union’s Salyut 7 (1991; ~40 tonnes), are the only higher mass events.

Artemis 1 Back on the Pad; Artemis 4 Regains Lunar Landing

NASA’s Artemis 1 mission, featuring the first launch of the space agency’s massive Space Launch System (SLS) rocket has returned to the launch pad at Kennedy Space Centre.

The vehicle, which is due to launch an uncrewed Orion vehicle to cislunar space, has seen numerous issues and delays in making its maiden flight, and was most recently held-up by the arrival of hurricane / tropical storm Ian in late September. The roll-out to Launch Complex 39B on November 4th marked the fourth (and hopefully last) trip back to the pad, departing the Vehicle Assembly Building at 04:00 UTC, and reaching the pad 8.5 hours later. Following arrival, work immediately began integrating the mobile launch platform on which the vehicle sits into the the pad systems in readiness for the next launch attempt.

A unique fisheye lens view of the Artemis 1 mission SLS vehicle moving out of the Vehicle Assembly Building, Kennedy Space Centre, at the start of its fourth journey to Pad 39B, November 4th, 2022. Credit: Joel Kowsky / NASA

If all goes according to plan, the rocket will lift-off on Monday, November 14th, at the start of an extended 39-day mission which will see the Orion vehicle and its service module spend some 15-16 days in a distant retrograde orbit (DRO) around the Moon before returning to Earth, with the uncrewed capsule splashing down in the Pacific Ocean off the coast of California. Providing no significant issues are encountered, the mission will pave the way for a second such flight in 2024/25- Artemis 2 –  carrying a crew. Then in 2027, Artemis 3 should undertake the first crewed landing on the Moon since the Apollo missions of the late 1960s / early 1970s.

in addition, NASA announced that Artemis 4 – the third crewed flight of an SLS vehicle to the vicinity of the Moon – will now include a lunar landing, marking a reversal to plans announced earlier in 2022. Under those plans, Artemis 4 was going to be a mission focused solely on the construction of the new Lunar Gateway station, due to be placed in a cislunar halo orbit in support of lunar landings. This was to allow time for NASA to switch away from using the SpaceX Starship-derived lander vehicle of  Artemis 3 with lander craft to be supplied under the Sustaining Lunar Development (SLD) programme.

Artemis 4 was to have focused on the assembly of the Lunar Gateway space station. However, it will now also include a lunar landing. Credit: NASA

However, NASA also has a so-called “Option B” in its contract with SpaceX that specifies the latter to develop and supply – funded by NASA – an enhanced version of the Starship lander, and it is believed that this option has now been exercised to enable a crew landing on the Moon with Artemis 4, which will still use the upgraded Block 1B version of SLS to deliver a crewed Orion vehicle and the Gateway station’s habitation module to lunar orbit in 2027.

In the meantime, Dynetics, one of the two contenders for the original Human Landing System (HLS) contract, has indicated it may well pursue the SLD contract, whilst Blue Origin, Lockheed Martin and Northrop Grumman – the three main  contractors in the so-called “National Team” and third contender for the original HLS contract – have indicated they will each independently pursue SLD  contracts, with Lockheed Martin examining the use of nuclear thermal propulsion (NTP) in it vehicle architecture, seeing NTP as a key element for future human exploration of Mars.

Starliner Will Not Fly to  ISS Until 2023

The first crewed flight of Boeing’s CST-100 Starliner to the International Space Station (ISS) has been further delayed to April 2023. However, the delay this time is not due to technical issues with vehicle, but rather to “deconflict” multiple planned arrivals at the station.

After a series of extended delays, Starliner finally completed an uncrewed flight to the ISS in May 2022,  the second attempt at such a flight after software issues with the original December 2019 mission left the vehicle unable to achieve a rendezvous with the station.

Boeing’s CST-100 Starliner capsule “Spacecraft 2”, docked at the International Space Station during the uncrewed OFT-2 mission in May 2022. Credit: ESA

Whilst this second uncrewed flight was a success, there were a number of minor issues which meant the hoped-for December 2022 crewed flight to the ISS – called the Crewed Flight Test-1 (CFT-1) – had to be delayed until  February 2023. However with a another crewed flight using a SpaceX dragon vehicle and a further resupply mission both due to reach the station in February 2023, the decision has been taken to slip the Boeing flight and reduce the volume of traffic arriving at the ISS in a relatively short time span.

SpaceX Completes 4th Falcon Heavy and Starship

Falcon Heavy Update

Tuesday, November 1st 2022 saw SpaceX complete the fourth successful launch and flight of its Falcon Heavy booster – currently the world’s most powerful operational launch vehicle.

The Falcon Heavy ascends towards orbit on November 1st, carrying the USSF-44 payload. Credit: NASA / SpaceX / DoD

The flight, out of Launch Complex 39A at Kennedy Space Centre, saw the rocket carry the classified USSF-44 mission to orbit, with the two “booster” elements of the rocket making a successful return to Earth, with a near simultaneous landing at Cape Canaveral Space Force Station adjoining Kennedy Space Centre.

The entire flight of the Falcon Heavy – essentially three Falcon 9 rockets strapped together – was subject to US Department of Defense (DoD) restrictions which meant video footage of the flight to orbit of the payload was curtailed moments after the vehicle’s upper stage had successfully separated from the core stage.

However, this did not prevent SpaceX livestreaming the launch and the return of the two “booster” Falcon 9 rockets to their successful landings – the core stage of the booster flew in the Falcon 9 “expendable” mode, sans guidance and landing systems, instead using all of its propellants to help push the multi-payload it bore all the way to orbit. Whilst ice and dirt did fog the cameras mounted on the sides of the two “booster” rockets during part of their return to Earth, this did clear before landing, allowing the cameras on the rockets as well as those on the ground to capture the moments both boosters touched-down at Landing Zones 1 and 2 at Cape Canaveral SFB.

As I noted in my previous Space Sunday update, demand for Falcon Heavy has not been especially high as the vehicle is simply too powerful for many launch requirements. However, the November 1st launch could be the first of a trio that might occur in short order: December could see a Falcon Heavy carry a ViaSat communications satellite to orbit, and then January 2023 could witness the second Falcon Heavy launch for the US Space Force on mission USSF-67, intended to deliver the second of the US military’s Continuous Broadcast Augmenting SATCOM (CBAS) satellites to orbit.

Starship: December Orbital Test Flight?

At a meeting of  NASA Advisory Council’s Human Exploration and Operations Committee on October 31st, Mark Kirasich, deputy associate administrator for Artemis Campaign Development at NASA, indicated that the agency believes that SpaceX could be in a position to carry out the first orbital flight test of its massive Starship / Super Heavy combination in December 2022.

NASA has been following the development of the vehicles closely due to it  selecting a modified version of the Starship orbital vehicle as the craft that will carry crews from lunar orbit to the Moon’s surface and back as a part of the Artemis 3 and 4 missions.

There are still a number of bridges to cross prior to any orbital flight test taking place – expectations on the part of SpaceX fans that October or November could see the flight occur were always wildly optimistic – but the signs are that SpaceX are proceeding through a step-by-step procedure that should satisfy the Federal Aviation Administration (FAA) that all requirements for Starship / Super Heavy flight testing out of Boca Chica, Texas, are being met and a launch licence therefore awarded.

Thursday, November 3rd: the stack of Booster 7 and Ship 24 undergoing cryogenic methane load tests, Boca Chica, Texas. Credit: NASA Spaceflightnow (not a NASA-affiliated site)

Most recently, the focus has most firmly been on the stack of Ship 24 and Booster 7 – both now regarded as the vehicle to be used in the first orbital flight attempt. Over the last few weeks both have been put through a series of cryogenic and propellant load tests which have seen liquid nitrogen used to initially fill their respective tanks before a such to loading actual propellants in each vehicle’s tanks on an alternate basis (e.g. first loading the respective liquid methane tanks, then vent / returning propellants to the tank farm prior to loading the liquid oxygen tanks and repeating).

It is believed this process of cycling tests is to ensure that all systems – vehicle tanks, propellant feeds, tank farm, etc., are all functioning correctly without risking a full load of propellants and a single-point failure leading to a potential detonation of volatiles. Between these tests, work has been carried out on both fitting additional elements to the base of Booster 7 and to the orbital launch mount to ensure both are ready for flight testing.

The next major test is liable to be a full static fire test of the 33 Raptor engines on the Super Heavy booster. This will likely be signalled by a further de-stacking of Ship 24 from the booster to minimise loss should the static fire test go sideways. After this, the vehicles will be restacked for a final full wet dress rehearsal, and then – assuming the launch license has been granted, the way will be clear for the orbital attempt.