Space Sunday: satellites, spacewalks and galaxies far, far away

IMAGE on its payload adaptor and being enclosed by its Delta II payload fairings, early 2000. Credit: NASA

In March 2000 a United Launch Alliance Delta 2 rocket lifted-off from Vandenberg Air Force Base, California. It was carrying NASA’s Imager for Magnetopause-to-Aurora Global Exploration (IMAGE), built by the South-west Research Institute (SwRI) Arizona, which was placed in a highly elliptical 1,000×46,000 km (625 x  28,750 mi) polar orbit, passing around the Earth once every 14.2 hours.

This orbit allowed the satellite to carry out its mission – to study the global response of the Earth’s magnetosphere to changes in the solar wind, the first ever such mission to be fully dedicated to an in-depth study of the magnetosphere – with great success. In fact, the mission was so successful, it was twice extended, from 2002 to 2005, and from 2005 through until 2010.

Or that was the plan. Unfortunately, on December 18th, 2005, the vehicle fell silent, missing a scheduled data transfer – which took place one average between once and twice a day. An earlier transfer the same day had passed without any indication the satellite was experiencing any problems. Despite numerous attempts to re-establish contact, IMAGE failed to resume contact with NASA’s Goddard Applied Physics Laboratory, responsible for managing the mission.

The mission was officially declared lost in September 2006. However, fault analysis suggested the satellite may have shut itself down as a result of a false indication of an short-circuit in part of its own power supply as the result of a ionised particle impact with it solid state power converter. This would cause the spacecraft to place many of its system in a “safe” mode. Engineers calculated that the vehicle could be recovered if the power converter could be tricked into resetting itself. Unfortunately, there was no means to manually trigger such a reset – but there was a potential for a reset to occur naturally.

Diagram of the IMAGE vehicle. The “tiling” on the visible sides and on the top of the craft are solar cells for generating power. Credit: NASA

As a result of its highly elliptical orbit, coupled with the Earth’s orbit around the Sun, IMAGE would spend an extended period in Earth shadow early in October 2007. If sufficient enough, the drop could trigger the desired reset.

Sadly, following the period of eclipse, no signal was received from the craft, and it was again considered lost. And it remained so, right up until January 2018, and the USA-280 spy satellite mystery.

In January 2018, the super-secret spy satellite no-one in the US government will admit to owning and code-named “Zuma”, was reported lost not long after launch. The nature of the mission and the mystery of its loss – which has still not been publicly confirmed – led radio hams and satellite trackers to scan the skies in attempts to locate the satellite’s transmissions.

On January 20th, 2018, one of these radio hams, Canadian Scott Tilley, detected S-band transmissions which he thought were from “Zuma”, and forwarded his findings to NASA. A  team from Goddard, using five separate antennae were able to confirm they were receiving transmissions consistent with expected frequency fluctuations in s-band broadcasts from IMAGE, on January 24th. Further, the signal had an oscillation consistent with the last known spin rate for IMAGE. Following this, on January 30th, analysis of further received data, the Goddard team were able to obtain an identification number from the craft: 166 – IMAGE’s “call sign”.

The challenge now is determining the spacecraft’s overall condition. This is a problem because the hardware and operating systems used to manage IMAGE no longer exist, so engineers are having to reverse-engineer current systems to analyse the received IMAGE signals. So far, this has allowed them to read some basic housekeeping data from the spacecraft, suggesting that at least the main control system is operational. The hope is that over the next several weeks, it will be possible to analyse IMAGE’s overall condition, and possibly even re-activate its on-board science systems. In the meantime, re-examination of old data recorded by Tilley and fellow satellite tracker Cees Bassa shows they picked-up transmissions from IMAGE in May 2017 and October 2016 without realising they had.

Discovering Planets in Another Galaxy

Exoplanets – planets orbiting stars other than our own – have been a subject of many of my Space Sunday reports. As of February 1st, 2018, 3,728 planets have been confirmed in 2,794 star systems, 622 of which have more than one planet. However, a study published on February 2nd, 2018 points to the first discovery of a planet in another galaxy.

Probing Planets in Extragalactic Galaxies Using Quasar Microlensing, by Xinyu Dai and Eduardo Guerras, a post-doctoral researcher and professor from at the University of Oklahoma’s Physics and Astronomy department, appeared in The Astrophysical Journal Letters. It outlines how the two used  Gravitational Microlensing to make their discovery, combining it with data on  a distant quasar known as RX J1131–1231, gathered by NASA’s Chandra X-Ray Observatory

RXJ1131-1231 is among the five best lensed quasars discovered to date. The foreground galaxy smears the image of the background quasar into a bright arc (left) and creates a total of four images — three of which can be seen within the arc. Image credit: NASA / ESA / Hubble / S.H. Suyu et al.

Gravitational Microlensing uses the gravitational force of distant objects to bend and focus light coming from a star. As a planet passes in front of the star relative to the observer (i.e. makes a transit), the light dips measurably, which can then be used to determine its presence. So far, 53 planets have been discovered within the Milky Way galaxy using the technique.

RX J1131–1231 is located 3.8 billion light years away and at its heart it has a super-massive black hole (SMBH). This has made it an ideal subject for a number of microlensing studies, including measuring the Hubble Constant – a fundamental quantity that describes the rate at which the Universe is expanding.

In this case, the team were able to use the microlensing properties of this black hole to observe line energy shifts among the quasar’s stars and study fluctuations within them which could only logically be explained by the presence of unbound – or rogue – planetary bodies between the quasar’s stars.

While none of the planets can be directly imaged, the team used the super computer facilities at the University of Oklahoma to analyse the high frequency of the microlensing signature. This provided them with some determination of the broad mass range of the planets, indicating they likely range in size from bodies roughly the size of the Moon up to planets at least the same size as Jupiter.

Prior to this study, the presence of planets in other galaxies had been hotly debated, with some doubting any such bodies could exist. Xinyu Dai and Eduardo Guerras have now opened the door for the discovery of planets far beyond our reach – abeit worlds beyond our ability to study them directly. Their work may also help refine our ability to detect planetary bodies much further afield in our own galaxy. What’s more, with the range of extremely large telescopes (ELT) currently under construction, such as the European Southern Observatory’s OWL (that’s “OverWhelmingly Large”) telescope, as well as new orbital facilities such as the James Webb Telescope, we’re bound to make more discoveries of planets within – and beyond – the Milky Way.

Russian Recording-Setting Spacewalk Ends In An “Oops”

On Friday, February 2nd, 2018, Russian cosmonauts Alexander Misurkin, currently in command of Expedition 54 aboard the International Space Station (ISS), and Anton Shkaplerov, the Expedition’s flight engineer completed the longest all-Russian spacewalk – or extra-vehicular activity (EVA) – in the history of Russian space endeavours.

Legs-up in space: Alexander Misurkin and Anton Shkaplerov appear to be upside down (arrowed) outside of the Zvezda service module, working on replacing the communication electronics unit. Credit: NASA

The EVA lasted 8 hours and 13 minutes, making it the fifth-longest spacewalk in history. The aim of the work was to upgrade to the communications system on the Russian Zvezda service module, and used for communications with Russia’s mission control centre near Moscow.

When first launched in 2000, the equipment was supposed to enable communication between the ISS and a suite of new generation of Luch (“ray”) communications satellites Russian was planning on launching. Unfortunately, ongoing financial  issues prevented Russian deploying the satellites until 2009 – by which time their electronics had been updated, making the communications system on the Zvezda module obsolete.

The new electronics unit was supposed to rectify this, and bring the Russian communications capabilities with the ISS up to par with American capabilities. Following the installation of the new 26.6 kg (60 lb) electronics package, the antenna would not redeploy correctly, causing Misurkin and Shkaplerov to use brute force, together with commands sent from Earth to get the antenna to deploy – efforts which extended the EVA by almost 2 hours.

While they were eventually successful, post-EVA analysis by NASA indicated the antenna is rotated 180-degrees further than required, leading to conflicting reports on whether or not this system is functioning as anticipated. When asked, Russia’s mission control only responded that the issue “is being evaluated”.

The disposed-of electronics module from the Zvezda service module tumbles away from the ISS, on Friday, February 2nd, 2018. Credit: NASA

A further point of interest with the spacewalk was the manner in which the old electronics unit was disposed of. US Astronauts, as a rule, recover replaced equipment for stowage on or in the space station. Those items which can be recovered to inside the station are often transferred to resupply vehicles such as Orbital ATK’s Cygnus so they burn-up with the vehicle when it detached from the station and set on a course to re-enter the atmosphere.

The Russians, however, tend to discard items into space, in the interests of “not contaminating” the station’s interior. Items tossed away can include replaced items of equipment through to towels used to polish the outside of the cosmonaut’s visors. In this case, the electronics suite – roughly the size of a briefcase – was thrown in a direction which will ensure it will not collide with the ISS, but will see it continue to orbit the Earth until such time as atmospheric friction drops it down to a point where it re-enters the denser atmosphere to burn-up.

A closer view of the electronics module tumbling away from the ISS, on Friday, February 2nd, 2018. Credit: NASA

One Giant Leap for Tourists?

At a time when western companies like Virgin Galactic and Blue Origin are planning to resume the nascent space tourism industry with sub-orbital flights, it has been reported that Russian space company Energia is planning a return to flying tourists to the space station  – but with a twist: the opportunity to make a spacewalks of their own whilst there.

According to reports, which quote Energia representatives, the company is designing a “hotel module” dubbed NEM-2. It unit appears to be a variation of the NEM Science and Power Module intended for the Russian element of the ISS due to be launched in  2020, and which could potentially become a cornerstone of a future Russian space station and a deep-space outpost.

An artist’s impression of the NEM Power and Science Module (lower left) and the NEM-2 “hotel module” (lower right) attached to the ISS via the upcoming Russian multi-purpose laboratory module. Credit: Anatoly Zak / RussianSpaceWeb.com

Also according to Energia, the new module has been financed through a mix of private and state investments,and estimates put the overall cost at between US $279 and $446 million. The 20-ton, 15.5-meter-long module will provide 92 cubic meters of pressurised space which will include four “bedrooms”, two toilets and will provide full internet access.

Figures suggest that the cost per head for tourists would be around US $40 million for a 7-10 day stay aboard the module. Those wishing to participate in an EVA outside of the space station would likely be charged an additional US $20 million for the privilege. The company plan to operate four tourist flights to the ISS per year, each one comprising two tourists and a professional cosmonaut. The cosmonaut will become a member of the station’s “regular” crew, while the tourists “holiday” in the NEM-2 module.

Were this idea come to fruition, it would mean Energia would likely recoup the cost of the module in around seven years – which is actually something of a problem. The ISS is due to be “retired” in 2028, and it’s unlikely the NEM-2 module, if it went ahead, would be ready for launch much before 2023, leaving little opportunity for the project to recoup its costs. As such, it’ll be interesting to see if anything comes of these reports.

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