NASA encouraged by initial TPS data

by Chris Bergin

The crew of Shuttle Discovery have successfully carried out inspections of the orbiter’s Thermal Protection System (TPS) – taking up the bulk of Flight Day 2 – ahead of tomorrow’s docking with the International Space Station (ISS).

Using the Orbiter Boom Sensor System (OBSS), inspections scanned for signs of damage on Discovery’s RCC (Reinforced Carbon Carbon) panels on her wing leading edges, and nosecap.

**Over 2100mb of STS-116 onwards related presentions and mission documentation available on L2 **

**LIVE news updates on Discovery STS-116 – FOR EACH FLIGHT DAY**

**LIVE news updates on Atlantis STS-117 (STS-317) Processsing Flow**

The images taken by the OBSS were relayed live to the inspection team on the ground, while high resolution images will be evaluated over the coming couple of days, for the purpose of focused inspection.

The OBSS is a key tool in checking the health of the TPS on orbit – and has already proven its usefulness on the three missions it has been involved on. Riding on the end of it’s boom, the sensor package is capable of spotting even the slightest mark on the key areas of the TPS.

The three main areas of inspection on Flight Day 2 were both the starboard and port wings and the nose cap of the orbiter. Thousands of images were taken, with focused evaluations on any area of interest being sent to the MMT (Management Mission Team). **CLICK HERE FOR PANORAMIC IMAGES OF TODAY’S INSPECTIONS**

Despite recent advances and modifications that have decreased the threat of critical damage to the orbiter during ascent – following the loss o Columbia on STS-107 – NASA are not taking any chances when it comes to missing any damage occurring on the orbiter during the ride uphill.

Understanding the debris environment an orbiter rides through on ascent has been aided by a series of sensors – or accelerometers – that are embedded under the 22 panels on each wing.

A recent Boeing presentation (available on L2) showed that the RCC panels still observed a number of ‘strikes’ on each of the previous three RTF (Return To Flight) launches, but importantly the mass of each strike are almost insignificant. Also, some of the ‘strikes’ can be caused by the shockwave that the Shuttle rides through, as noted by Boeing.

Those sensors – which is part of the ‘early warning system’ for debris concerns – contain immediate data that can help point to areas of interest for the OBSS to check in the event of a ‘focused inspection’ – which will take place on Flight Day 5, if required.

Following the conclusion to the inspections today, Deputy Shuttle manager John Shannon noted that only four ‘strikes’ were recorded by the RCC Panel sensors, all occurring after the key stage of ascent where debris can cause damage to the protective skin of Discovery.

‘Today we held our first MMT and the early indications are that everything on the Shuttle performed very well,’ Shannon noted, before mentioning some minor issues with the Flash Evaporator System – which provides additional cooling to the orbiter radiators – and the loss of RMS (Remote Manipulator System) End Effector Auto Release capability.

‘The team sees nothing of concern at this time, but we did see four possible impacts (via the sensor readings), but of a very low momentum transfer (grms). The readings equate to one tenth of what we calculate to cause any damage and we’ve seen this before on previous flights at about the same time.’

Other areas that need to be checked include the belly of Discovery. This will be carried out during tomorrow’s arrival at the ISS, with the highlighted RPM (Rendezvous Pitch Manoeuvre) rolling Discovery upside down, thus allowing photography to be taken by ISS crewmembers.

Discovery is due to dock with the ISS Tuesday afternoon.

Super high quality (450meg) Launch Videos of STS-116 is now available on L2. Several HQ Engineering Videos also available.

**INFINITY: 10 minute STS-115 MUSIC VIDEO** –
(Video section is FREE, but you need to sign up as a member of the forum to enter the video section of the site. We only use your e-mail to send you your password. It will not be used for spam etc.)

** Job Opportunities** 

Related Articles