Space Sunday: Dream Chasers Falcons, and spacewalks

The Dream chaser alongside NASA's space shuttle Atlantis

The Dream Chaser flight test article alongside NASA’s space shuttle Atlantis in 2010 (image: NASA / SNC)

NASA has announced a renewal to the current US private sector contracts to provide uncrewed resupply missions to the International Space Station (ISS) – and it came with something of a surprise.

SpaceX and Orbital ATK are the two US companies currently flying cargo resupply missions to the ISS, operating alongside Russian Progress vehicles and the Japanese H-II “Kounotori” Transfer Vehicle. Europe, which previously operated the largest cargo vehicle, the Automated Transfer Vehicle, ended ISS resupply missions in February 2015, and is now focused on supplying NASA with the Orion Service Module.

Both SpaceX, who can both launch and return up to 3.3 tonnes of cargo and trash to / from the space station using their Dragon cargo vehicle, and Orbital ATK,who can transport up to 3.5 tonnes of cargo / trash aboard their Cygnus vehicle (which burns-up on re-entering Earth’s atmosphere) have their resupply contracts renewed from 2019 through 2024, matching the extended lifetime of ISS operations. While this had been expected, the inclusion of a third vehicle, the Dream Chaser vehicle being developed by Sierra Nevada Corporation SNC surprised some.

Dream Chaser was unique among the commercial crew transportation proposals as it was based on a "lifting body" design , allowing to re-enter the Earth's atmosphere and glide to a landing on a conventional runway - aspects which still make it a very flexible vehicle

Dream Chaser was unique among the commercial crew transportation proposals as it was based on a “lifting body” design rather than a capsule system. Although launched atop a conventional rocket, the design allows it to re-enter the Earth’s atmosphere and glide to a landing on a conventional runway, making it an exceptionally versatile craft (image: SNC)

Dream Chaser was originally designed as part of NASA’s Commercial Crew Development (CCDev) programme aimed at having private sector companies provide the means of carrying crews back and forth between the space station and US soil. One of four proposals put to NASA under the programme, it was ruled out of the final selection in September 2014, with SpaceX and Boeing being chosen by NASA despite the fact that on paper, Dream Chaser offered potentially a better deal than Boeing’s CT-100 capsule.

While SNC lodged a complaint with the US Government Accountability Office (GAO) as a result of the decision, citing interference in the selection process by William Gerstenmaier, NASA’s top human exploration official, the GAO upheld the selection of SpaceX and Boeing for the crewed transport vehicles. However, NASA continued to work with SNC on various ideas for Dream Chaser, alongside of SNC looking at other options for the vehicle’s crew carrying capabilities to be put to use.

An artist's concept of the Dream Chaser Cargo docked with the ISS during a resupply flight

An artist’s concept of the Dream Chaser Cargo docked with the ISS during a resupply flight (image: SNC)

The new resupply contract will see SNC provide NASA with the uncrewed “Dream Chaser Cargo” variant of the vehicle, capable of flying up to 5 tonnes of cargo to / from orbit, As with the original crewed variant, the Dream Chaser Cargo will launch atop a rocket, but return to earth to make a conventional runway landing.

How many missions each of the three resupply vehicle types will fly is unknown; vehicles will be selected on the basis of flight / payload requirements and cost. The total cost of the contract, spilt between the three companies, is expected to be US $14 billion over the 5 years.

The Ice Volcanoes of Pluto

Scientists with NASA’s New Horizons mission have assembled the highest-resolution colour view of one of two potential cryovolcanoes spotted on the surface of Pluto, as the spacecraft hurtled by the little world in July 2015.

Informally called “Wright Mons”, the feature is about 150-160 kilometres (90-100 miles) across at its base, and about 4 km (2.5 miles) high. If it is in fact a volcano, it will be the largest such feature discovered in the outer solar system.

The feature has members of the New Horizons science team intrigued on two counts. The first is that there is a very sparse distribution of red material on its flanks. The second is that it apparently only has a single impact crater. This latter point suggests “Wright Mons” is relatively new surface feature on Pluto, while the former might suggest it is active, with ice ejected by eruptions covering the red material over time.

"Wright Mons" (the large dimple in the image on the right) and as seen in context with the rest of Pluto, may be one of two enormous cryovolcanoes on the tiny world (image: NASA/JPL / JHU/APL / SwRI)

“Wright Mons” (the large dimple in the image on the right) and as seen in context with the rest of Pluto, may be one of two enormous cryovolcanoes on the tiny world (image: NASA/JPL / JHU/APL / SwRI)

The images of “Wright Mons” were returned to Earth from New Horizons in November 2015. Since then, data from the Ralph instrument suite aboard the spacecraft has been used to add the colour details to the images, which have been composed into a new mosaic of the feature. If it and “Piccard Mons” are cryovolancoes, then they present further evidence that Pluto was (and might still be) geologically active.

SpaceX Launches Jason 3

On Sunday, January 17th, 2016, SpaceX successfully launched the NASA / European Jason-3 satellite into a near-polar orbit from Vandenberg Air Force Base, California.

Jason-3 is part of a very long-term series of studies (started in 1992) to study the topography of the ocean surface (i.e. the formation and movement of waves and the troughs between them), which can provide scientists with critical information about circulation patterns in the ocean, and about both global and regional changes in sea level and the climate implications of a warming world.

Jason-3, the latest in a series of joint US-European satellites studying the topography of the ocean's surface, successfully launched by SpaceX on Sunday, December 17th, 2016

Jason-3, the latest in a series of joint US-European satellites studying the topography of the ocean’s surface, successfully launched by SpaceX on Sunday, December 17th, 2016

The polar orbit used for this kind of earth-observing mission, being almost perpendicular to the Earth’s rotation, allows the spacecraft to at some point travel over almost every part of the world’s oceans, vastly increasing its ability to gather data when compared to a vehicle in an equatorial orbit.

Following the launch, SpaceX made a further attempt to recovered the first stage of their Falcon 9 1.1 booster by having it fly back for a landing aboard their autonomous droneship, Just Read the Instructions, moored and waiting off the Californian coast. If successful, the return of the Falcon 9 would have marked the second successful recovery of an orbital rocket’s first stage (SpaceX having achieved the first, land-based recovery in December 2015), and the first such recovery to successfully occur at sea (three other attempts by SpaceX having failed).

Unfortunately, after successfully manoeuvring itself back to the droneship, the first stage of the Falcon 9 rocket struck the automated platform a little harder than anticipated, breaking one of its landing legs, resulting in it toppling over on the deck.

With the towing vessel for the autonomous droneship approaching in the background, a photo from one of the landing support vessels shows the Falcon 9 1st stage toppled over on the landing ship's deck after one of its legs broke on touchdown

With the towing vessel for the autonomous droneship approaching in the background, a photo from one of the landing support vessels shows the Falcon 9 1st stage toppled over on the landing ship’s deck after one of its legs broke on touchdown

In the meantime, the first stage which did successfully land at Cape Canaveral Air Force Station, Florida, in December has been fully inspected and is now undergoing refurbishment ready for a further launch in the future.

Spacewalk Good for Tim, Not So Good for Tim

Friday, January 15th, 2016, saw British astronaut Time Peake undertake an important EVA – extra vehicular activity – outside the International Space Station. working with  NASA astronaut Tim Kopra – who will be taking over as the station’s commander later in the mission – Peake completed a difficult operation to replace a voltage regulator which had failed in November 2015, reducing the amount of electrical power available to the station by an eighth.

The repair was part of a planned 6-hour spacewalk, and had to be completed in the 31 minutes the space station was in the “night” of Earth’s shadow, in order for the astronauts to avoid any risk of electrical shock from the station’s solar power system. While completed well within the time limit, the repair was one of special significance. The failed regulator is located some 61 metres (200 ft) from the station’s EVA airlock, and sits at the very limits of the space station reachable via EVA.

Tim Peak manoeuvres the replacement voltage regulator - dubbed "Dusty" by the crew - in this photo taken by Tim Kopra

Tim Peake manoeuvres the replacement voltage regulator – dubbed “Dusty” by the crew – in this photo taken by Tim Kopra

The replacement unit was also something of an unknown: it has been sitting aboard the space station waiting to be used for 17 years; despite being checked-out beforehand, there were concerns that the unit – roughly the size of a 30-gallon container and dubbed “Dusty” in respect of its age – might not accept being finally put to use.

Following that repair, Peake and Kopra moved on to other tasks before Kopra made a worrying announcement: water was gathering inside his spacesuit helmet, prompting mission control to call a halt to the EVA and instructing the astronauts return to the station so that Kopra’s suit could be checked.

A selfie by Major Tim during his EVA, the camera visible in the reflection in his helmet visor

A selfie by Major Tim during his EVA, the camera visible in the reflection in his helmet visor

The measure was purely precautionary; at no point was Kopra in danger. However, the incident was cause for concern because, in 2013, Italian astronaut Luca Parmitano came very close to drowning when 1.5 litres of water escaped from his spacesuit’s cooling system, much of it into his helmet – and Kopra was wearing the same suit. As it turned out,  just 15cc’s of water escaped into Kopra’s helmet. NASA engineers have launched an investigation into the issue, the suit having been subject to repairs and improvements in light of the Parmitano incident, and having been used safely on EVAs since then.

The spacewalk also marked the first time the Union Flag had been worn on an EVA space suit, a point not lost on current mission Commander Scott Kelly, who called Peake over the radio as he exited the station’s airlock, saying, “Hey Tim, it’s really cool seeing that Union Jack go outside. It’s explored all over the world. Now it’s explored space!” The Englishman replied, “It’s great to be wearing it, a huge privilege, a proud moment.”

Current station commander Scott Kelly (top) is flanked by Kopra and Peake after their return to the station, to discuss Kopra's suit issue

Current station commander Scott Kelly (top) is flanked by Kopra and Peake after their return to the station, to discuss Kopra’s suit issue

To mark “Major Tim’s” achievement, and in memory of David Bowie, I’m going to close this Space Sunday report the only way suitable: a video of Space Oddity, Bowie’s timeless hit which reach No 5 in the UK when released in 1969. The video is of what is said to be the first performance of the song on television, originally recorded in 1970.

 

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