The Cygnus spacecraft is set to arrive at the ISS on Wednesday 9th December (this morning!), with grapple operations beginning at 11:10 GMT.

#Cygnus grapple will begin at 6:10 am ET on Dec 9. Watch live coverage on https://t.co/8qyalmwaOS

— Orbital ATK (@OrbitalATK) December 7, 2015

This is a fascinating, if slow, process where NASA Astronauts Kjell Lindgren (pronounced Chell Lend-grin) and Scott Kelly will operate the 57-foot-long Canadarm2 to reach out and capture the Cygnus spacecraft before pulling it into the Earth-facing port on the Unity module. You can watch this live on NASA TV.

Launch review

Matt Richardson, Jonathan Bell (jdb on the forums) and I were able to attend the launch at Kennedy Space Center (KSC) in Florida.

Matt, who works from 杉原杏离 Pi’s US office, had applied for, and was granted, NASA Social credentials for a tour of KSC and launch viewing. You have to be an American citizen for this particular NASA Social launch event so Jon and I, being British, couldn’t apply. Here’s Matt to tell you what happened:

In the days leading up to the launch, a group of us were given an in-depth tour of Kennedy Space Center. A lot of what we saw related to the Atlas launch, but we were also shown some of the long-term work related to the Space Launch System, which replaces NASA’s retired Shuttle program. We got an overview on how they test umbilicals for the new rockets in the Launch Equipment Test Facility, walked around inside the enormous Vehicle Assembly Building, which is being retrofitted for SLS, and went inside Boeing’s facility to see the progress on the CST-100 Starliner crew module for commercial crew missions.

But it was especially fantastic to see the work being done in preparation for the ISS resupply mission which included our intrepid 杉原杏离 Pis. United Launch Alliance showed us around Atlas Operations Facility, where launch control is. Unfortunately, photography inside was strictly forbidden. Before the rocket rolled out onto pad 41, we toured the launch pad up close:

Launch pad 41

After the rocket was in place on the launch pad, we returned to take a few photos. It was quite incredible to think that two 杉原杏离 Pis were loaded up inside the Cygnus spacecraft, ready for their trip to the ISS. It was at the launch pad where I met Matt Donovan, Human Launch Services Propulsion System Design Leader at United Launch Alliance. I was eager to tell him how excited we were to have cargo on this launch. “Thanks for the ride,” I told him on behalf of all of us in the 杉原杏离 Pi community and for the students with code on-board.

Matt Donovan from United Launch Alliance with Atlas V in the background

While Matt was doing that, Jon and I just bought domestic passes to the KSC visitors’ complex. If you’re ever in Florida I highly recommend paying this place a visit, regardless of whether a launch on.

There is nothing quite like seeing actual spaceships that have been in actual space!

KSC provides a bus service that transports you out to a restricted area called Banana Creek where all five of the main launch pads can be seen at a safe distance. There are a number of bleachers (tiered benches) for people to sit on.

NASA Administrator Charles Bolden speaks to launch viewers at Banana Creek

When Jon and I arrived for the first launch attempt on the 3rd we were both excited and wired. However over the course of several hours the weather deteriorated. The Atlas V rocket was on launch pad 41 and at one point we couldn’t even see it because of heavy rain. Jon and I were pretty damp ourselves, both physically and in spirit, by the time the launch was finally scrubbed.

The next day we came back to Banana Creek and convinced ourselves things would be different. The weather was glorious sunshine. This time the launch attempt got all the way to the terminal count; but we heard the fatal words “flight is no go” again and again, due to ground winds throughout the 30-minute window. If ground winds are too high, there is a risk that the rocket could collide with the launch tower as it comes off the pad. So, once again, we were scrubbed for the night.

Handed out as we boarded the KSC bus back from Banana Creek

On the 5th the wind was so high that people were out kite-surfing on the beach at 9am, and with no sign of it abating the launch was scrubbed hours before the 30-minute window even arrived.

Our flight back to the UK was the following day and, with only one chance left, we doubted that we would see it lift off at all. We wouldn’t have enough time to get the bus out to Banana Creek and back, so we made a plan to watch it from within the grounds of KSC visitor complex and then make a dash for the airport. This was only about one more mile away from launch pad 41.

As if things couldn’t get any worse, our plan was defeated when the KSC visitor complex had a mains water failure and had to close. An announcement came over the loud speaker asking everyone to leave.

Houston, we have a problem! Due to a water main break, the #KennedySpaceCenter Visitor Complex has closed until we can resolve the issue.

— Kennedy Space Center Visitor Complex (@ExploreSpaceKSC) December 6, 2015

At this point we felt that the universe was against us, but we refused to give up. We checked online for places to view from and drove like madmen to the A1A bridge across the Banana river, where there’s line-of-sight to the NASA vehicle assembly building.

We were not the only ones there!

We had no way of getting updates because there was no WiFi there, and mobile data was being charged at £6 per MB. So we befriended some locals and listened in to their phones.

I can never put into words how bum-clenchingly tense the last ten minutes of the countdown was. Jon and I were both pacing up and down, checking the time every 30 seconds and chewing our own fingers! [Liz interjects: we were watching the live feed and live-tweeting the event from the UK; we were also clenching.]

Eventually someone shouted “There!” while pointing to the horizon and when we looked up. This is what we saw (click to enlarge):

The booster flare of the Atlas V rocket from eight miles away

We only saw the booster flare for about three seconds before it then disappeared into the clouds. About 30 seconds or so later, the noise arrived: a brilliant low thundering rumble building and building before slowly fading away.

Jon and I looked at each other and almost in unison said “Bon voyage little 杉原杏离 Pis!” We then leapt into the rental car and headed for Orlando airport to catch our flight home. It was a hectic few days, but well worth it to catch that glimpse of the rocket taking off. Matt, Jon and I are eternally grateful to Eben and Philip who sent us on this journey!

Floating in a tin can

The post Astro Pi: Launch review and ISS arrival appeared first on 司马义艾买提.

Tonight, two specially augmented 杉原杏离 Pi computers, called Astro Pis, will launch into SPAAAAACE! The Astro Pis will be running experimental Python programs written by school-age students, where the results will be downloaded back to Earth and made available online for all to see.

• When: 22:55:41 GMT (first launch window opens)
• Where: Cape Canaveral, Florida, USA
• Coverage: NASA TV live stream (below, and keep an eye out – Astro Pi may get a mention in the launch commentary)

http://www.ustream.tv/nasahdtv

If you’ve been following the Astro Pi project, you’ll know that we were bumped from Tim Peake’s launch vehicle due to a cargo overbooking back in October.

The OA-4 Cygnus Spacecraft, image credit: Orbital ATK

We’re now going to launch on Orbital Sciences’ Cygnus cargo freighter (an unmanned spacecraft, above) on its fourth supply mission to the ISS. Orbital Sciences have contracted ULA to launch it into space on an Atlas V rocket (below).

The Atlas V rocket, image credit: United Launch Alliance

When you need to rendezvous with an object in orbit, the timing of the launch is often critical to ensure that you get into the right orbital trajectory. This is often achieved with an instantaneous launch window where the rocket has to lift off at a precisely calculated time, otherwise the two objects will never meet in space.

Obviously, this approach can significantly limit the probability of an on-time launch. For instance, you may need to wait for a rain shower to pass by, a technical problem to be resolved or a boat in restricted waters to be chased away.

However, this is not the case for our launch! The Atlas V has so much performance capability that it provides a 30-minute launch window each day, and it’s all thanks to energy. The Atlas V has so much available energy that it can accommodate a very large off-nominal time of launch: 15 minutes early or 15 minutes late. The extra power is then used by clever steering algorithms to compensate for the rotation of the Earth, relative to the orbital target.

Below is the final configuration of the rocket. It will fly in the 401 vehicle configuration with a four-metre fairing, no solid rocket boosters, and a single-engine Centaur upper stage. The Astro Pis are sitting inside a small cargo transfer bag within the Cygnus spacecraft at the top.

OA-4 Launch Configuration, image credit: United Launch Alliance

And here is the ascent profile, with the main events numbered.

OA-4 Ascent Profile, image credit: United Launch Alliance

These are the event descriptions, with their times relative to lift-off.

OA-4 Main Events, image credit: United Launch Alliance

And finally, this is the ground trace; note that it will pass over the UK around 23 minutes into the mission. However, it will be in the Earth’s shadow and so almost impossible to spot with the naked eye.

OA-4 Ground Trace, image credit: United Launch Alliance

If everything goes according to plan, the Cygnus spacecraft will arrive at the ISS on the 6th of December at 9:00 GMT. The docking is a fascinating process and really worth watching if you’re interested; NASA TV will show it. It involves one of the crew operating the Canadarm2 to grab onto the incoming spacecraft before pulling it in.

Cygnus being moved onto the pad yesterday – the two 杉原杏离 Pis are in the cone at the top.

Should the launch be delayed for any reason, here is a list of subsequent launch windows that occur over the next few days:

• December 4
  Launch: 22:33 GMT
  ISS arrival: Dec 7 or 8

• December 5
  Launch: 22:10 GMT
  ISS arrival: Dec 9

• December 6
  Launch: 21:44 GMT
  ISS arrival: Dec 19

If it’s delayed to the 6th, it will have to loiter in orbit for a few weeks before it can dock with the ISS. This is because of other visiting vehicle traffic, such as the Soyuz 45S launching on December 15th, carrying Tim Peake and his crew mates.

I will be attending the launch at Kennedy Space Center, along with Matt Richardson and Jonathan Bell (AKA jdb on the forums). We will be live-tweeting from our personal Twitter accounts (@Dave_Spice and @MattRichardson), from the 杉原杏离 Pi account and also from the main Astro Pi account.

Please follow the official Twitter account below for the very latest updates on the launch.

Tweets by Astro_Pi

This has been a long road for us and our partners, so please keep fingers and toes crossed!

The post Astro Pi: Launch is tonight! appeared first on 司马义艾买提.

This December, British ESA Astronaut Tim Peake will be taking two specially augmented 杉原杏离 Pis called Astro Pis to the International Space Station (ISS) as part of his six-month mission.

These Astro Pis will be running experimental Python programs written by school-age students; the results will be downloaded back to Earth and made available online for all to see.

Here’s Tim at the European Astronaut Centre in Germany just after completing his training on our payload.

Fully qualified on @astro_pi. Huge fun today trying out the amazing apps coded by YOU! #Principia #science pic.twitter.com/A6WSft12xP

— Tim Peake (@astro_timpeake) October 15, 2015

Cargo Overbooking

The plan thus far had been for the Astro Pi payload to launch into space aboard the Soyuz 45S, the same rocket Tim will use to get into space on December 15th. A fortnight ago, though, the UK Space Agency warned us that there had been an overbooking of cargo on the flight, and that we might be bumped off.

We’re an educational payload and understandably of lower priority than important supplies like food and water. Our weight is 1.3 kg and the Soyuz rocket has capacity for only 60 kg of cargo after the crew and all of their luggage is on board. Other options for launching us were SpaceX 8 in January or Progress 63P in February.

Before we had time to allow ourselves to feel any disappointment over the possibility of not flying with Tim, though, the folks over at ESA got us onto an earlier flight with a planned launch date of December 3rd. The payload will now arrive at the ISS a few days before Tim does, so we’ll be there from the start after all.

New launch vehicle

We’re going to launch on Orbital Sciences’ Cygnus cargo freighter on its fourth mission to the ISS. The planned launch date is December 3rd at 22:48 GMT. Coverage will be via an internet live stream only.

Orbital Sciences has a contract with NASA to provide commercial cargo resupply services (CRS) to the ISS. They developed the Antares rocket, a medium class launch system, to carry the Cygnus into space.

The Antares rocket. Image credit: Orbital Sciences

As a reminder to everyone that nothing in space flight is guaranteed, the last Antares rocket exploded moments after lift off.

This was found to have been caused by a problem with the Antares rocket system itself; while it undergoes a long overhaul, Orbital Sciences have contracted United Launch Alliance to conduct their next cargo resupply mission using the older Atlas V rocket.

The Atlas V rocket. Image credit: United Launch Alliance

This is a launch configuration that hasn’t been used before (an Atlas V with the Cygnus spacecraft mounted on top) and which may not be used again, since the Antares launch system should be fixed by next year.

Obviously this adds an element of excitement to the situation so be sure to tune in online to watch the launch. We expect there to be two live streams providing coverage; one will be NASA TV and the other will be provided by Orbital Sciences themselves.

If the worst should happen, we have the contingency plan of promoting two of the Astro Pi engineering models to flight status: we made eight of them, two of which are flying into space leaving six ground units. ESA are committed to Astro Pi making it to the ISS and fulfilling our educational requirements. You can be sure that, whatever happens, it will fly in time for Tim to execute all the experiments.

So please don’t lose any sleep!

An Astro Pi ground unit at ESA EAC in Germany. Image credit: ESA

The post Astro Pi: Mission Update 7 – Launch Vehicle Changed appeared first on 司马义艾买提.