Uhuru, also known as the X-Ray Explorer Satellite or SAS-1 (for Small Astronomical Satellite) was an orbiting observatory, specifically for X-ray astronomy (the first of its kind). It was launched from the Italian San Marco offshore launch platform off the coast of Kenya on December 12th 1970, Kenyan independence day, hence the post-launch choice of a new name, which, as all good Star Trek fans know, is the Swahili for “freedom”. Its three year mission was to seek out new X-ray sources via a survey of the entire sky.
Uhuru was the first US satellite to be launched by another country. Under the terms of a memorandum of understanding between NASA and the University of Rome, the Americans provided the rocket and satellite, while the Italians were responsible for the assembly and launch (following training with NASA in Virginia). The site was chosen principally to enable easier access to an equatorial orbit than would be possible from Cape Canaveral (which would have needed a much larger rocket).
The joint mission was very successful, with Uhuru producing a catalog of some 300 X-ray objects during its three years, mostly binary systems and supernova remnants.
On this day in 1910, Indian astronomer Subramanyan Chandrasekhar was born in Lahore. Chandrasekhar studied at Cambridge University, but spent most of his working life at the University of Chicago. He is mostly remembered by the astronomical community for showing that a white dwarf star cannot support a mass greater than 1.44 times that of the Sun. This is now called the Chandrasekhar limit. If the star has a mass in excess of this limit, it will eventually collapse to form a neutron star or a black hole.
Chandrasekhar was awarded the 1983 Nobel Prize in Physics for his work on the evolution of stars, but it was a long time coming. He had been made a Fellow of the Royal Society in 1944, awarded the Gold Medal of the Royal Astronomical Society in 1953, and the Henry Draper Medal (awarded every 4 years for research in astronomical physics) in 1971. Following his Nobel Prize, the Royal Society honoured him with the Copley Medal (the world’s oldest scientific award still being given out) in 1984.
The International Gamma Ray Astrophysics Physics Laboratory (INTEGRAL) was launched on this day in 2002 by the European Space Agency. 2002 was quite a while ago in spacecraft life-spans, but INTEGRAL is still going strong, and still producing plenty of results. The launch was provided by the Russian state-owned Roscosmos corporation, and took place at the Baikonur Cosmodrome, using a Proton-K rocket.
Highlights of the mission so far have included:
observing, in conjunction with the Fermi and Swift space observatories, gamma ray jets near a supermassive black hole using gravitational microlensing;
taking part in a multi-observatory study of blazar TXS 0506+056, an active galactic nucleus, and a source of high energy neutrinos;
collecting data on the unusual behaviour of the black hole of V404 Cygni during its 2015 outburst;
studying “AT2018cow”, the brightest stellar explosion ever recorded, and possibly the birth of a black hole or neutron star.
The joint UK/USA satellite ArielV was launched by Scout B-1 solid fuel rocket, on October 15th 1974 from the Italian Space Agency’s San Marco platform off the coast of Kenya. It was an x-ray observatory, with a camera and a variety of instruments provided via NASA and the (now defunct) UK Science and Engineering Research Council. Operations were controlled from the Rutherford-Appleton Laboratory in Oxfordshire.
Ariel V was the fifth of six Ariels, launched between 1962 and 1979. It’s orbit decayed on March 14th 1980. The name is probably a nod to the works of one of Britain’s biggest exports, William Shakespeare (I say this because our only other early satellite was called Prospero).
Ariel V produced several highlights, discovering long-period x-ray pulsars and x-ray transients (Nature, vol 261, 1976).
Telstar 1, launched from Cape Canaveral on July 10th, 1962, marked a significant jump in the evolution of global communication. It provided the first ever relay via space of television, telephone and telegraph images.
The Telstar project was an international affair, involving the US, UK, and France. It was also responsible for the building of the first dish at Goonhilly Downs in Cornwall, a visit to which, in the 1970s, I remember as being partly responsible for my fascination with astronomy and spaceflight (Patrick Moore provided the rest of the inspiration).
Built by Bell Labs, Telstar was designed to fit inside the US Delta launch vehicle, and it’s one of those things that I find hard to work out the size of from a photograph. It’s actually just a little bigger than a large yoga ball (34.5 inches diameter). Telstar was put into an off-centre orbit, varying between under 600 and over 3,600 miles above the Earth. It’s still up there, and it’s altitude means it will probably remain up there for a very long time.
Unfortunately Telstar’s working life was severely curtailed by the effects of radiation from a high-altitude nuclear test (amazingly there was nothing unusual about that in the 1960’s). It failed in November 1962, just four months after launch. But that was still long enough to handle a few hundred telephone and telegraph messages, and to transmit a game of baseball and a speech by John F Kennedy. They managed to get it working again in January 1963, but once again, radiation (this time solar) proved Telstar’s downfall, shutting it off for good in February.
SAMPEX was the Solar Anomalous and Magnetospheric Particle Explorer. It was launched on July 3rd 1992 from Vandenberg Air Force Base in California on a ScoutRocket (and was RIP Nov 13, 2012).
SAMPEX’s instruments were far more sensitive than those of previous similar missions, which allowed a great deal of new information to be gathered on the composition of interstellar gas, the mechanism of solar atmospheric heating and the relative abundance of various isotopes.
As you can see from the photograph, SAMPEX was quite dinky. This is because it was an early success of NASA’s Small Explorer Program, orSMEX. (Why not SEX? They could have improved their hit rate on Google by loads.)
FUSE(the Far Ultraviolet Spectroscopic Observer) was launched using a Delta IIvehicle (number 7320) on June 24th 1999 from Cape Canaveral. (Unnecessary aside: cañaveral is Spanish for reed bed.)
FUSE provided value for money, for a change. Designed to operate for three years, it actually kept going for eight, until a failure in the system used to point it accurately at targets rendered it effectively useless in September 2007.
FUSE was part of NASA’s ongoing Origins program, a collection of space- and Earth-bound observations designed to help get rid of some of those pesky, really fundamental questions about the Universe that are proving so hard to answer (such as where it came from, and whether anybody else lives in it).
The main aims of FUSE in this were to study (i) the amount of deuterium (a hydrogen isotope) out there, and (ii) the chemical evolution of galaxies. FUSE was able to study over 3000 targets during its eight year life; not just distant galaxies and quasars either, but also stars, planets and comets.
The idea behind using FUSE to measure deuterium was (very basically) that the amount we can measure today might be used to determine the conditions present at a stage in the evolution of the Universe before atoms as we know them today existed.
1852 – S-type asteroid 18 Melpomene(the Greek muse of tragedy) discovered by John Russell Hind.
1915 – Birth of Sir Fred Hoyle, in Gilstead, a village on the outskirts of Bingley, Yorkshire. Sir Fred was no shrinking violet when it came to expounding his views. He was opposed to the idea that life on Earth began here from scratch, had his own theory of gravity (disproved) and preferred the “steady state” theory of the universe rather than the stupendously more popular “Big Bang”. Ironically though, Hoyle is credited with coining the phrase big bang.
I’m never sure whether to call these things Cosmos or Kosmos. Cosmos is probably better because I’m not trying to speak Russian; but Kosmos starts with a “k”, which the actual name does. But then, if I’m going to do that, should I not go the whole hog and say Космос? Anyhoo . . .
Cosmos 427 was launched from the Plesetsk or Pleseck (or even Плесе́цк, if you must) Cosmodrome on June 11th, 1971. The aim was to insert a 4,000 kg satellite into orbit, and for this the Russians turned to the Voskhod variant of the world’s first intercontinental ballistic missile, the R-7 (or the “A-1” as it was known in the West in 1974 when my Observer’s Book of Unmanned Spaceflight was published).
Kosmos 427 spent a fairly short time in space: 12 days. It’s orbit decayed on June 23rd, 1971. Not that this was anything for the ground crew to worry about; the actual payload of this particular flight was a Zenit-4MK reconnaissance satellite, all of which were given the name “Kosmos” to hide their true purpose, which would almost certainly have been to spy on the USA or one of her allies. This being the early 1970’s, the easiest way to do this was to launch a collection of cameras into orbit, get them to take loads of photos, and then arrange for them to fall back to Earth at a place of your choosing.
Today’s visual aid is almost certainly not a Zenit-4MK, but a Zenit-4MT. But there is very little difference in the basic design: something looking like two-thirds of a vary large ant goes up, and the big sphere at the top comes back down full of pictures.
Just in case you were wondering, Kosmos satellites were launched sequentially, from “1” upwards, meaning the number 427 really does signify the 427th in a quite staggering sequence of launches.
The European X-Ray Satellite (EXOSAT) was launched on May 26th 1983, and was operational until April 9th 1986, studying x-ray binaries, active galactic nuclei, and other x-ray sources. Personally I think the best thing about it was its bizarre orbit (from 120,000 mile apogee to 300 mile perigee), but there were other highlights of the three years, including the discovery of quasi periodic oscillations in LMXRBs and x-ray pulsars. I can sense that you are just dying to know what LMXRB stands for. It’s Low Mass X Ray Binary (low mass is a little misleading, generally meaning lower in mass than the Sun).
1969 – Apollo 10splashdown. Tom Stafford, John Young and Eugene Cernan were recovered by the USS Princeton, about 400 miles from American Samoa, in the Pacific Ocean. Their 8-day mission had included four orbits of the Moon, as a rehearsal for “the big one”, which was to take place later the same year.
1826 – Birth, in Chelsea, of Richard Christopher Carrington, recipient of the Gold Medal of the Royal Astronomical Society. His work included the demonstration of the existence of solar flares, and their influence on our planet. He now lends his name to the numbering system for sunspot cycles.
Discoverer 2 was launched on April 13th, 1959 from Vandenberg Air Force Base into a 239 x 346 km polar orbit via a Thor-Agena booster. It was a large cylindrical satellite, 1.5 metres in diameter, 5.85 metres long, and a hefty 3800 kg, designed to gather data for use in future missions, and to attempt ejection of an instrument package from orbit for recovery back down here. This part of the plan was attempted on 14 April 1959, when a reentry vehicle was ejected, with the idea that it would come down somewhere conveniently near Hawaii for recovery. Unfortunately, due to a malfunction, reentry was over the north polar region, and the capsule remains officially unrecovered, although there are those who say Soviet agents got to it first. It has been suggested that this episode was partly the inspiration for Alistair MacLean’s novel, Ice Station Zebra.
Discoverer 2 successfully gathered a great deal of data on propulsion, communication, and stabilization. It was the first satellite to be stabilized in all three axes, and the first to be maneuvered by commands from Earth.
1906 – Discovery of asteroid 598 Octaviaby Max Wolf. Octavia is a C-type asteroid of approximately 72 km diameter. It was named for the prominent Roman noblewoman Octavia the Younger, sister of the emperor Augustus, fourth wife of Marc Antony, and great-grandmother of Caligula. Octavia’s marriage to Marc Antony only lasted a few years before he abandoned her in favour of an old girlfriend, Cleopatra VII of Egypt.
In today’s picture, supposedly an actual historical event, Octavia is seen swooning on hearing Virgil reading a passage from Book VI of the Aeneid. The book contains details of the famous people encountered by Aeneas in the underworld, one of whom is Octavia’s son Marcellus (by her first husband), who had died at the age of nineteen. The shock of hearing it is supposed to have caused Octavia to have fainted with grief.