I heard it clearly: CNN announced
that Iran had put a monkey in orbit.
Several news sources also mentioned that the United States could not
confirm the story. So what’s the truth?
The truth is that CNN apparently
was hoodwinked by an astonishingly misleading press release from the Iranian
press agency, which used the word “satellite” to describe a mere probe. The Iranian launch was on a Kavoshgar 3 ballistic missile capable of
attaining 100 km altitude but far too slow to achieve orbital velocity. The monkey flew a parabolic trajectory that
reached 120 km altitude, but certainly did not circle the Earth. American radar and optical tracking stations
regularly monitor all satellite traffic, and infrared-sensing military
surveillance platforms in geosynchronous orbit high above the equator keep an
eye on all rocket launches. But neither
of these tracking systems is equipped with a monkey detector. Anything that gives off lots of heat is fair
game: bored staff members at USAF Space Command used to pass the time by
checking whether the trains on the Trans-Siberian Railroad were keeping to
their schedules. But a train gives off
far more heat than a monkey.
So why is 100 km altitude
considered “space”? The answer is quite
simple: 100 km is the lowest altitude at which a typical satellite can survive
for a single orbit against the retarding forces of air friction. Satellites with unusually large area (such as
a large expanse of solar cells) and low mass experience more drag deceleration,
and would not last for even one orbit at this altitude before reentering the
atmosphere and burning up. Compact,
dense satellites (such as those launched to study Earth’s gravitational field)
would last a little longer. But for
typical satellite designs, surviving one orbit (about 87 minutes) at 100 km
would be about normal. Besides, 100 is
such a nice, round number.
And what does “in orbit” mean? It means that the object is following a
ballistic (un-propelled) path that will take it all the way around a body such
as Earth or the Sun. For orbits around
Earth, that means at least a 40,000 km trip.
The Iranian monkey launch traveled about 200 km, not 40,000, and briefly
reached a maximum altitude of 120 km.
Not that Iran can’t launch small
satellites: it has already done so three times, in 2009, 2011 and 2012. A real orbital mission with a monkey aboard
is a possibility for the future. The
remarkably uninformative press release by the Iranian press agency tells
nothing about the launch, but does mention that the purpose of this flight is
to prepare for manned spaceflight—and adds that the launch was in celebration
of Mohammed’s birthday. The Director of
the Iran Space Agency, Hamid Fazeli, recently announced that Iran plans to send
humans on “half-hour” space flights “within four years”. This is clearly not orbital flight, and I
expect that “half hour” will eventually be found to mean “quarter hour”. He also claimed that Iran will be ready for
manned orbital flight within 10 years.
By then, the intrepid Iranonaut may find himself unnoticed among the
swarms of Western space tourists.
Who, if anyone, should care about
this monkey mission? Israel, which is
within reach of Iranian ballistic missiles such as the one used in this launch.
In other satellite-related Iranian
news, I see from a posting at http://www.ncr-iran.org/en/news/society/12720-iran-regime-is-fearful-of-use-of-satellite-in-villages
that Iran is confiscating satellite dishes from its citizens as part of its
“cultural offensive”. Certainly,
“offensive” is the operative word here.
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