Space Sunday: rockets, planets and Martian helicopters

The Trump Administration has ordered NASA to achieve a human return to the Moon by 2024

After US space agency NASA indicated their schedule for the new Space Launch System (SLS) rocket is to undergo revision, with launches liable to be pushed back, the White House has stepped in with an apparent contradiction: NASA is to accelerate plans to return humans to the Moon, achieving the goal no later than 2024 –  a target that requires a fully operational SLS.

The order came via an address by Vice President Mike Pence at a meeting of the National Space Council on March 26th in Huntsville, Alabama. He couched the order in terms of addressing rising concerns about delays to SLS and the “threat” of international competition. However, alternative views are that the demand is more about the Trump administration trying to achieve a Kennedy-like legacy before any possible second term for the administration has expired.

Following the address, NASA Administrator James Bridenstine backpedalled away from statement made two weeks previously, in which he indicated that NASA would look at options for initial flights of the completed Orion capsule and its European-built Service Module using commercial launch vehicles, rather than relying on the SLS, to allow more time for troublesome elements of that vehicle to be completed. Instead, NASA will now attempt to focus on getting the SLS up and running for the initial Exploration Mission flights, themselves seen as necessary precursors to a Moon landing.

NASA’s plans for the human exploration of the Moon and Mars rely on the SLS – but the plans themselves have always been woolly. The White House is seeking to give aggressive focus to the lunar element – perhaps to aggressive. Credit: NASA

As I’ve noted in recent Space Sunday reports, there are some significant issues around the SLS core stage and its advanced Exploration Upper Stage (EUS) that has been seen as crucial to lunar operations. The issues with the latter were such that Brindenstine had indicated it would be placed on hold, and NASA would utilise the less powerful Interim Cryogenic Propulsion Stage (ICPS) at the rocket’s upper stage. Following Pence’s announcement, the NASA Adminstrator confirmed the emphasis would be back on getting the EUS completed, and a 45-day study has been initiated to determine how development of the rocket’s core stage might be accelerated.

One of the ideas for the latter that is being floated is to cut a “green run” test of the first completed core stage main engines at full power for 8 minutes, which would require the completed stage being shipped from the Michoud Assembly Facility, Louisiana, to the Stennis Space Centre, Mississippi, and instead deliver the completed  stage directly to Kennedy Space Centre for integration with the rest of the vehicle for its first launch. This would cut several months from the launch schedule, but also leave the stage untested.

The massive core stage of the SLS is a massively complex undertaking, and somewhat behind schedule. Credit: NASA

Bur even with such cuts, the 2024 goal is regarded as a “very aggressive goal”. To achieve it, NASA will not only have to accelerate work on the first SLS vehicle, they will need an increase in funding across multiple related projects. For example, following the first two EM launches, NASA would need to gear-up to two SLS launches a year in order to lay the groundwork for a lunar landing – including placing the initial elements of the Lunar Gateway in orbit around the Moon. This alone requires the building of a second mobile launch platform (yet to be funded by Congress).

Another issue is what will happen to the robotic precursor missions seen as stepping-stones towards a human mission. Currently, it is unlikely any of these will be ready to fly before 2021 – and no formal contracts have been awarded to the nine companies competing to fly them. Then there is the not insignificant question about the development and testing of the actual lunar lander vehicle. As such, while some organisations have responded enthusiastically to Pence’s announcement, others have sounded more cautionary notes.

Though we support the focus of this White House on deep space exploration and the sense of urgency instilled by aggressive timelines and goals, we also are cognizant of the resources that will be required to meet these objectives. Bold plans must be matched by bold resources made available in a consistent manner in order to assure successful execution.

– The Coalition for Deep Space Exploration

In order to meet a 2024 goal, many programmes would have to be accelerated: SLS, the Lunar Gateway, the development of a lunar lander, etc. Credit: NASA

Even some in NASA have voiced very public misgivings against the acceleration of goals given the overall state of the SLS and supporting programmes.

Do you want to kill astronauts? Because this is how you kill astronauts. There’s no reason to accelerate going to the Moon by four years. It’s ridiculous. 

– Holly Griffith Orion Vehicle Systems Engineer, speaking to AFP.

Certainly, if NASA is to meet a 2024 target date, it will need something of an increase in funding – and this is where Pence’s words fall flat: For 2020, the Trump Administration is seeking to decrease NASA’s budget by half a billion dollars compared to 2019 actual budget – and actually seek to decrease spending on SLS by 17.4% compared to 2019.

WFIRST on the Chopping Block. Again

Another programme hit by the Trump 2020 NASA budget proposal is the astrophysics flagship mission, the Wide Field Infrared Survey Telescope (WFIRST).

WFIRST’s layout and instruments. Credit: NASA

As I’ve previously noted in these updates, the Trump Administration tried to cancel WFIRST in their 2019 budget proposal, citing in part its expense – this despite the mission being one of the most cost-effective on NASA’s books, given it is able to use a lot of parts developed as back-ups to the Hubble Space Telescope – including the 2.4 metre diameter primary mirror.

A second reason for the 2019 cancellation – which was prevented by Congress – was a claim that WFIRST “duplicated” work to be undertaken by the James Webb Space Telescope (JWST), and other aspects of the WFIRST mission could be achieved via “cheaper” means. In actual fact, WFIRST and JWST are able to mutually support one another’s mission, rather than duplicating mission elements. Nevertheless, it is the ongoing delays with JWST which are now being pointed to as the reason to de-fund WFIRST, the argument being that until JWST is launched, WFIRST isn’t a priority.

NASA Administrator Brindenstine has suggested WFIRST’s funding could be brought back up to speed once JWST has been deployed. The problem here is that once a project has been de-funded, it can be very difficult to revive, as doing so tend to foreshorten desired time frames in order to get a mission launched, resulting in much larger additional costs than might have been the case had funding been allowed to continue through the intervening years. Further, 2020 is a crucial year from WFIRST: a design review for the overall mission is scheduled for October, and is due to be followed by what is called “Key Decision Point C”, and formal mission confirmation. Without funding, these milestones cannot be reached, potentially leaving the project in an uncomfortable limbo.

TESS Finds a “Hot Saturn”

TESS – the Transiting Exoplanet Survey Satellite – launched from Florida’s Cape Canaveral Air Force Station on April 18, 2018 has been hard at work, spending month-long periods scanning individual “strips” of the galaxy with its four cameras, seeking planets beyond our solar system (see: Space Sunday: of exoplanets and naming Charon’s features).

In particular, TESS has a target list of around 25,000 Sun-like oscillating stars – stars with a wobble in their spinning which might be the result of the presence of one or more planets orbiting them, and one of them, referred to as only TOI-197 (TOI = Tess Object of Interest), has been found by TESS to be the home of at least one planet.

An artist’s impression of TOI-197 and its planet, TOI-197.01. Credit: Gabriel Perez Diaz, Instituto de Astrofísica de Canarias

The star is  about 5 billion years old, roughly the same age as the Sun, whilst being slightly larger and heavier. The planet orbiting it, designated  TOI-197.01, is a gas planet with a radius about nine times the Earth’s, making it roughly the size of Saturn. It’s also 1/13th the density and about 60 times the mass of Earth. It is exceptionally close to its parent, orbiting it once every 14 terrestrial days – which probably makes it a turbulent world.

Not much else is known about the planet, but it is one of the first to have been confirmed as a TESS discovery. Such is the wealth of data being returned by the satellite, an international team of 141 astronomers are involved in sifting their way through it.  What is particularly interesting about this discovery is that while TOI-197 was identified as an oscillating star, it was actually asteroseismology – the study seismic waves (or “starquakes”) in stars that appear as changes in brightness, that helped confirm the presence of the planet close to the star – marking one of the first such instances where asteroseismology has been used, TESS being specifically equipped for this purpose.

This is the first bucketful of water from the fire hose of data we’re getting from TESS. TOI-197 provides a first glimpse at the strong potential of TESS to characterise exoplanets using asteroseismology.

– Steve Kawaler, professor of physics and astronomy, Iowa State University

TESS is intended to complete its survey over a two-year period. However, with the amount of data so far returned, coupled with the wealth of information within it, astronomers believe it is likely that  – like Kepler – TESS will have its mission significantly extended.

 NASA’s Mars Helicopter Completes Flight Tests

NASA’s next rover  – the Mars 2020 mission, due for launch next year for a 2021 arrival on Mars – is due to carry a number of scientific packages. However, perhaps the most novel element of the mission is not the rover itself, but the helicopter it will carry with it.

The tiny drone – weighing some 1.8 kg (4.4 lbs) – will be powered by batteries that are recharged via solar cells. Carried in a mechanism under the body of the rover, the helicopter will be lowered to the ground once a suitable location for deployment has been found. Then, after the rover has moved clear, it would be allowed to take flight (see Space Sunday: Flying on Mars, working on the Moon and visiting Europa for more).

The Mars helicopter demonstrator: set to fly with the Mars 2020 rover mission. Credit: NASA

Recently, the core components of the actual helicopter that will go to Mars were put through a comprehensive test programme, logging over 75 minutes of flying time mounted on an engineering model that replicates the helicopter’s frame. These tests were completed under Mars-like conditions in the Jet Propulsion Laboratory’s Space Simulator vacuum chamber. This was used to recreate a carbon-dioxide atmosphere typical of Mars at Martian surface pressures. In addition, a gravity offload system was used to simulate Mars’ gravity. This used a motorised lanyard attached to the helicopter to provide an uninterrupted tug equivalent to two-thirds of Earth’s gravity, allowing the engineering team working on the helicopter to carry out a series of test flights that have shown the little drone will likely operate on Mars.

The next time we fly, we fly on Mars. Watching our helicopter go through its paces in the chamber, I couldn’t help but think about the historic vehicles that have been in there in the past. The chamber hosted missions from the Ranger Moon probes to the Voyagers to Cassini, and every Mars rover ever flown. To see our helicopter in there reminded me we are on our way to making a little chunk of space history as well.

– Mimi Aung, Mars Helicopter project manager

The Mars Helicopter test model – using actual flight elements for the mission – is prepared for a trial flight under Mars conditions in the Space Simulator at NASA’s Jet Propulsion Laboratory, California. Credit: NASA/JPL

Once on Mars, the helicopter, which is more a proof of concept vehicle, will carry out up to five flightsover a 30-day period. The first will be very short-duration, enough to allow the helicopter to ascend to around 3 metres (9 feet) and hover for 30 seconds while the flight systems are checked out. Later flights will last up to 90 seconds and travel as far as a few hundred metres before landing to allow the solar panels to recharge the battery system.

 

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