The odd bit

Once is an accident, twice is a coincidence, three times is an enemy action.

The odd bit - Once is an accident, twice is a coincidence, three times is an enemy action.

Landing day for Endeavour

Today is homecoming day for space shuttle Endeavour. The crew has been given the go for deorbit. The deorbit burn will take place in about 2 minutes at 17:25 CET. The landing at the Kennedy Space Center (KSC) Shuttle Landing Facility will take place around 18:32. If anything important happens, you’ll read it here.

The vehicle was cleared for landing earlier in the mission after NASA engineers and managers spent a week analysing one damaged area. The area got hit by a piece of foam from the external tank during the launch. Thermal assessments of the damaged tiles revealed that they don’t pose a threat to crew and vehicle safety during re-entry. A final post-docking inspection of the Thermal Protection System revealed no other damaged areas.

Updates (all times CET):

  • 17.24h: Good config for the burn.
  • 17.25h: Deorbit burn started!
  • 17.30h: Deorbit burn complete! The 1-hour trip to Earth’s surface has started.
  • 18.01h: Endeavour is now at the point called Entry Interface.
  • 18.04h: Mission Control warned the crew about a period of intermittent communications around the point of the first roll reversal.
  • 18.07h: First banking maneuver happens about now. This is used to bleed off excess speed.
  • 18.17h: As it just crossed Central America, Endeavour is now heading towards Cuba as it enters its first roll reversal.
  • 18.20h: Communications have been restored as the shuttle passes over Cuba.
  • 18.26h: And there she is! Visual contact at an altitude of over 80000 feet about 7 minutes from touchdown.
  • 18.29h: We just heard the famous double sonic boom.
  • 18.31h: The crew just reported the runway being in sight. She sure looks beautiful gliding down to the runway!
  • 18.32h: Gear down and locked.
  • 18.33h: Main gear touchdown… and nose gear touchdown!
  • 18.34h: Wheel stop!
  • 18.42h: The crew and Mission Control are now going through the procedures to put the vehicle in a safe configuration.

These are the official times given by NASA:

  • Main gear touchdown at 18:32:16 (Mission Elapsed Time [MET] of 12 days 17 hours 55 minutes 34 seconds)
  • Nose gear touchdown at 18:32:29 (MET of 12 days 17 hours 55 minutes 47 seconds)
  • Wheel stop at 18:33:20 (MET of 12 days 17 hours 56 minutes 38 seconds)

NASA Launch Day: STS-118 (Endeavour)

Space shuttle Endeavour is about to lift off from Cape Canaveral in about 1 hour and 40 minutes. It’s the first flight for Endeavour in years as it has gone through an extensive modification period. STS-118 is another mission to the International Space Station and will deliver the S5 truss segment and cargo.

The weather conditions are remarkably good for today’s launch. About 6 hours before the launch, the weather officer reported only a 20% chance of weather preventing a liftoff. 3 hours later, isolated showers were removed from the forecast dropping the chance of weather preventing a liftoff to just 10%.

At this time, the crew is seated in the space shuttle and comm checks are complete. The big orange fuel tank is fully loaded with liquid hydrogen and oxygen. The launch team is tracking no issues at this time. For people in Europe, the launch time will be 9 August 0.36h.

Status updates after 22.50h (CET):

  • 22.52h: The Closeout Crew reported an issue with what they call “micro-switches” on the crew hatch. They will reopen and close the hatch again to try to get a good seal.
  • 23.08h: The Mission Management Team have had a discussion about a small crack in the external tank foam near the liquid oxygen feedline support bracket. The conclusion is that there’s no debris issue and the tank is safe. The Closout Crew continues to work on the hatch, trying to verify that the hatch is indeed closed.
  • 23.15h: Two technicians are now in the White Room to verify that the orbiter’s crew hatch is indeed closed.
  • 23.21h: We’re at T-20 minutes and holding for 10 minutes.
  • 23.23h: The launch team has verified that the orbiter’s crew hatch is closed! Cabin leak checks are now in progress.
  • 23.31h: T-20 minutes and counting. We’ll have another hold at T-9 minutes which will last about 45 minutes.
  • 23.42h: T-9 minutes and holding. The hold will last exactly 41 minutes and 52 seconds.
  • 0.11h: The weather is “green” for all TAL-sites (Transoceanic Abort Landing).
  • 0.27h: T-9 minutes and counting!
  • 0.34h: T-2 minutes!
  • 0.36h: Liftoff of Endeavour!
  • 0.39h: Good SRB separation!
  • 0.41h: Negative return. This means Endeavour can no longer return to KSC in case of an emergency.
  • 0.44h: Endeavour’s looking good. Approaching MECO…
  • 0.45h: MECO (Main Engine Cut-Off)
  • 0.46h: Clean external fuel tank separation

Endeavour is in its preliminary orbit after what appeared to be a very smooth ride to space. Rendez-vous with the ISS is scheduled for Friday.

Atlantis landing: Day 2

Space shuttle Atlantis takes another attempt at trying to land. The first attempt was waved off due to bad weather at Kennedy Space Centre. KSC isn’t looking good for the second attempt either and NASA is now targetting Edwards Air Force Base in California. That’s on orbit 219 which has an opportunity for both KSC and Edwards.

Conditions at Edwards are currently looking good and the space shuttle crew has been given the go for fluid loading (= drinking lots of fluids to aid in the transition to Earth’s gravity). If given the final go, the deorbit burn would happen at 2:43pm EDT (20:43 CET) and the landing at 3:49pm EDT (21:49 CET).

  • 20:20: Atlantis is go for the deorbit burn. The burn will happen in a little over 20 minutes.
  • 20:23: Atlantis will now be positioned to perform the deorbit burn. The burn happens tail first, or retrograde, which slows Atlantis’ orbital speed with about 200 mph. That will put it the shuttle on a re-entry path.
  • 20:41: Mission Control reports a good config for the burn.
  • 20:43: The propulsion officer at Mission Control reports that the burn is in progress with the 2 engines performing normally.
  • 20:47: Deorbit burn complete!
  • 20:52: Atlantis will be repositioned from tail-first to nose-first, or prograde, for entry interface (the point where Atlantis starts to experience the first effects of Earth’s atmosphere) and re-entry.
  • 21:18: Less than one minute until entry interface.
  • 21:19: Entry interface takes place at an altitude between 125 and 130 kilometers with the orbiter more than 8000 kilometers away from the landing site. It then takes around half an hour to stop on the ground.
  • 21:36: Atlantis is on track for a landing at Edwards in 13 minutes.
  • 21:38: Atlantis is now within range of the tracking stations at Dryden, NASA’s flight research centre.
  • 21:42: And we have visual contact with Atlantis!
  • 21:47: Atlantis crew reports runway in sight.
  • 21:49: Full stop on runway 22 of Edwards AFB! Atlantis has safely landed!

STS-117 was the 118th space shuttle flight and this landing was the 51st at Edwards.

The Atlantis crew will now go through post-flight checklists before leaving the orbiter. The orbiter needs to be flown back to KSC for post-flight processing. A ferry flight on top of a Boeing 747 could take place after 7 days.

Atlantis landing delayed

Space shuttle Atlantis was scheduled to land at Kennedy Space Centre today. The first attempt on orbit 202 at 1:55pm EDT and the second attempt on orbit 203 at 3:30pm EDT have both been waved-off due to bad weather above the shuttle landing facility.

There will be four opportunities tomorrow: two at Kennedy (orbit 218 @ 2:16pm and orbit 219 @ 3:51pm EDT) and two at Edwards Air Force Base in California (orbit 220 @ 5:21pm and orbit 221 @ 6:56pm). For those in Europe, that’s 20:16, 21:51, 23:21 and 0:56 CET. There are also opportunities available on Saturday.

Kennedy is the preferred landing site for several reasons. If the shuttle lands at Edwards, it needs to go on a piggyback ride on top of a Boeing 747 to bring it back to Kennedy. That flight can only happen when the weather is good and even then it’s still a big risk. Such a flight is not only risky, but also expensive. Landing at Edwards also means it’ll take longer before the post-flight processing can begin. To summarise, landing at Kennedy is less risky, cheaper and faster to get the orbiter back in ready state.

The fans and the curious can watch the landing on NASA TV.

Launch day for Atlantis

We’re within 6 hours of a possible launch and that means NASA has activated the launch blog. Current weather conditions are red, but the forecasts give only a 20% chance of weather blocking a launch.

Status updates:

  • 20.08h: The inspection team (or “ice team“) is looking at a hanging bracket on the mobile launcher platform to see if it could become a safety issue.
  • 20.40h: The clouds are moving away and predicted weather conditions for launch are still green.
  • 21.24h: A couple of showers off-shore, but they should not be an issue for the launch.
  • 21.45h: The Final Inspection Team has left the pad.
  • 22.38h: 3 hours left until T-0.
  • 23.05h: The go to close and seal the orbiter’s hatch has been given.
  • 0.02h: T-20 minutes and holding. Everything’s green.
  • 1.03h: There were weather problems with the TAL (Transoceanic Abort Landing) sites in France and Spain. Istres (France)is now go though.
  • 1.24h: And Atlantis is go for launch!
  • 1.38h: Lift-off!
  • 1.41h: SRB separation.
  • 1.46h: Main-Engine Cut-Off and external tank separation complete.

Atlantis ready for duty

We’re about 27 hours away from Space Shuttle Atlantis‘ launch. Conditions are looking good with only a 20% chance of weather violating the constraints. The launch of mission STS-117 was initially scheduled for sometime in March, but a hail storm decided otherwise. After repairs to both the orbiter and the external tank, the whole system is good to go for tomorrow’s launch at 7.38pm EDT (I believe that’s 1.38am CET).

Tomorrow’s launch will also be the first in a long time from launch pad 39A. Pad 39B has been used for launches lately while 39A received some maintenance. Pad 39B has now been deactivated for shuttle operations, so 39A will serve as the launch pad until the shuttle fleet is retired.

Stardust@Home

About a year and 9 months ago, the Stardust spacecraft returned to Earth after its encounter with comet Wild-2 a year earlier. The craft was equipped with an aerogel collector to capture comet particles. Scientists estimate that Stardust also collected around 45 interstellar dust particles. That would be the first time ever and the search to find them in the aerogel has started.

Because it would take years to complete the search, the people at the Space Sciences Lab @ Berkeley decided to ask volunteers to look at scanned images of the aerogel and identify the tracks left by the interstellar particles. And the volunteer they’re looking for is you! The Stardust@Home project provides you with so called focus movies, a series of images of one point with a different focus. Then it’s up to you to spot the tracks left by dust particles.

Before you can do the real stuff you need to take a little test to see if you’re up to the task. But it’s not that hard and they have tutorials and stuff. Interested? Go and register!

Pluto: From Planet To Dwarf Planet

The cat is out of the bag: Pluto is no longer a planet. The International Astronomical Union (IAU) made that decision during its 26th General Assembly. Celestial bodies in our Solar System can now be defined into three categories:

  1. A “planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
  2. A “dwarf planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
  3. All other objects except satellites orbiting the Sun shall be referred to collectively as “Small Solar-System Bodies”.

This means our Solar System now has 8 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The first members of the dwarf planet class are Pluto, Ceres and 2003 UB313. Pluto is considered to be the prototype of a new class of Trans-Neptunian Objects (TNO). The third category currently includes most asteroids, most TNOs, comets, …

I think this decision is much better than the initial proposal where they’d promote Ceres and Pluto’s satellite Charon to the class of planets. Recent findings indicated that Pluto is in fact a Kuiper Belt Object and that the region contained more Pluto-like objects. This added more fuel to the discussion about Pluto’s status as a planet which has now ended with the IAU’s decision.

STS-121: Launch Time – Take 3

Yesterday’s crack in the external tank’s foam and the subsequent foam loss has been cleared by the Mission Management Team and Discovery has been given the green light for today’s launch countdown.

The weather is looking good with only a 20% chance of weather prohibiting a launch. If everything is “go” this will be the first shuttle launch on Independence Day. The launch should happen around 20:38 CET.

Update: Things continue to go well for the shuttle, but there’s one thing to watch. The sea breeze causes cross winds at the runway. The runway is used in case a return-to-launch-site abort is issued. Speed limits for crosswinds to guarantee a safe landing are set at 15 knots and the wind keeps flirting with the limit. An average speed will be calculated later on.

There was also an issue with a back-up circuit breaker. It controls the primary heaters on the segment joints of both SRBs. The “Red Team” was going to head down to the mobile launcher platform to replace the failed circuit breaker, but the launch team decided to fly in the current condition. There is no problem flying with just the main circuit breaker functioning.

We’re now at T-9 minutes and holding for another 31 minutes.

Update 2: The wind issues are gone according to Mission Control in Houston. All team members have been polled and we are counting again!

There may be an unscheduled hold at T-31 seconds to allow the LOX (liquid oxygen) inlet temperatures to drop to normal levels. The temperatures are slightly higher than the past few days and they need to be right in order to start the engines.

We’re now at T-5 minutes and counting.

Update 3: And what a smooth ride it was! Not a single problem during liftoff and ascent. It has completed main engine cut-off (MECO) and external tank separation is complete. Two astronauts will now take footage of the external tank and downlink it later in the flight for analysis.

I did not notice the T-31 seconds hold so I assume it did not happen. Discovery is in space!