The Alpha Magnetic Spectrometer (AMS-02) is a particle physics module mounted on the ISS. It is designed to detect and measure antimatter in cosmic rays and search for evidence of dark matter.
The instrument has been called “the most sophisticated particle detector ever sent into space”, and is considered by many to have the best chance of discovering evidence for the existence of dark matter. Dark matter is invisible matter that although cannot be directly detected, is believed to make up 23% of the Universe. Along with dark energy, it means that just 4-5 percent of the Universe is made up of visible matter, like the stars we see at night.
The 14,809 lb (6717 kg) module was launched by the Space Shuttle Endeavour for STS-134 on May 16 2011 and installed 3 days later on the 19th. AMS-02 is located on top of the Integrated Truss Structure, on a section known as USS-02. The mission has so far lasted almost 4 and a half years, and is expected to last for at least another five years, bring a full mission duration to a decade.
Following a year of data collection the AMS-02 had recorded over 18 billion cosmic ray events. One of the key results produced from this data has been the theory that positrons originate from the annihilation of dark matter particles in space. However, Professor Samuel Ting warned that although this theory is consistent with the data collected, it is “not yet sufficiently conclusive to rule out other explanations”. The experiment is just one example of many that proves the ISS is an incredible scientific outpost that is beneficial for the advancement of scientific discoveries.
On October 28 astronauts Scott Kelly and Kjell Lindgren conducted a spacewalk to install a new thermal cover for the AMS. The covers provide thermal performance for parts of the system that have been operating for longer than their life span of 3 years.
SpaceX have selected ORBCOMM-2 as the payload for the first flight of the Falcon 9 rocket since the CRS-7 failure in late June. Expected to take flight in early to mid-December, the upgraded rocket will lift a group of 11 mini-satellites to low Earth orbit.
As you may recall, on June 28 the Falcon 9 rocket suffered a catastrophic anomaly that resulted in the disintegration of the launch vehicle and a premature end to the mission. It had been hoped the rocket would deliver the Dragon spacecraft to orbit, where it would rendezvous and dock with the International Space Station.
Following the failure, the bright minds at SpaceX worked day and night to come up with a credible cause of the catastrophe. Initial findings pointed towards an overpressure event in the second stage of the Falcon 9. These initial findings held strong, as a couple of weeks later a preliminary report was produced which specified a failed strut that released a helium bottle, causing an overpressure event in the tank and a failure of the stage and rocket. This explanation has remained the primary cause of the failure and SpaceX are now going through the steps in order to formalise it, with the FAA currently reviewing the evidence.
The return to flight has been long awaited. Prior to the mishap it was hoped that the Falcon 9 rocket would lift around a 6 more payloads to space in the second half of 2015, including NASA payload Jason-3, a couple of CRS missions, and a number of commercial satellites. The failure of CRS-7 has stalled this progress, meaning just a couple of missions are possible, with SpaceX aiming for early December and late December launches of two missions, ORBCOMM-2 and SES-9. With a short turnaround time in which to launch these payloads, delays are likely.
SpaceX will use this flight as a test ahead of SES-9. Once the ORBCOMM satellites have been safely deployed in their specified orbits, SpaceX plan to relight the second stage . This is useful ahead of the SES-9 flight as it will require a second firing of the Merlin Vacuum engine.
In a statement SpaceX said, “This on-orbit test, combined with the current qualification program to be completed prior to launch, will further validate the second stage relight system and allow for optimization of the upcoming SES 9 mission and following missions to geosynchronous transfer orbit.”
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