“Vanguard rocket on launching pad.”
Based on the appearance of the rocket in the below linked photos, I think this is Vanguard Test Vehicle-Two/Vanguard TV-2. Since it’s venting, possibly taken the night/early morning of its October 23, 1957 launch?
Per Wikipedia:
“Vanguard TV-2, also called Vanguard Test Vehicle-Two, was the third suborbital test flight of a Vanguard rocket as part of Project Vanguard. Successful TV-2 followed the successful launch of Vanguard TV-0, a one-stage rocket launched in December 1956 and Vanguard TV-1, a two-stage rocket launched in May 1957.
Project Vanguard was a program managed by the United States Naval Research Laboratory (NRL) and designed and built by the Glenn L. Martin Company (now Lockheed-Martin), which intended to launch the first artificial satellite into Earth orbit using a Vanguard rocket.[1] as the launch vehicle from Cape Canaveral Missile Annex, Florida.
Vanguard TV-2 arrived at Cape Canaveral in June 1957. Vanguard TV-2 was a prototype as it had a liquid rocket first stage, a dummy (no fuel) second stage, and a dummy (no fuel) third stage. Three Vanguard stages were needed to put a satellite in orbit, the final goal of the Vanguard project. Since stage two and three had no power, the test flight would not achieve the same height as Vanguard TV-1.
Vanguard TV-2 lifted off on 23 October 1957 from Cape Canaveral from launch pad LC-18A. Launch pad 18A was an older Viking launch stand that was shipped from White Sands Missile Range for use at the Cape Canaveral. Pad 18A was also used on Vanguard TV-0 and TV-1. The goal of TV-2 was to test the final Vanguard first stage, as well as to test the retrorocket system of stage two and spin-up of stage three. Also new to test on TV-2 flight was a super high frequency (SHF) C-band radio beacon on the rocket and ground tracking radar gear, used to track proper propulsion and trajectory. The telemetry was picked up at the Air Force Missile Test Center's (AFMTC) tracking station.
Vanguard TV-2 was successful, the three-stage rocket achieved an altitude of 175 km (109 mi), a down range of 539 km (335 mi), and a top speed of 6,840 km/h (4,250 mph). TV-2 landed in the Atlantic Ocean. First and second stage separated on time, all controls and tracking worked. The only problems TV-2 had were on the ground getting ready for the flight, as there were many delays. TV-2 was shipped to the Cape not working (agreed and known by all parties). It took from early June to late October in 1957 at the Cape to work out all the problems that were not fixed in the manufacturing. For contrast TV-1 arrived at the cape in February 1956 and lifted off in early May 1956. The delay of TV-2 along with the failure of TV-3, put the United States behind in the Space Race. On 4 October 1957, 19 days before TV-2's lift off, a Soviet Union Sputnik rocket was used to perform the world's first satellite launch, taking away some of the joy of TV-2's success.”
Above at:
en.wikipedia.org/wiki/Vanguard_TV-2
The linked images/associated descriptions upon which my identification is based:
“First stage of one of the Vanguard rockets being erected in the gantry at the Navy's launching site at the Air Force Missile Test Center. After the rocket has undergone tests, it is combined with "dummy" second and third stages and fired sometime soon to test its new GE 27,000 pound thrust engine under actual flight conditions. U.S plans to send earth satellite during IGY with this missile.”
www.gettyimages.com/detail/news-photo/first-stage-of-one-...
“Satellite test rocket to be fired soon. This Vanguard rocket is known as TV-2.”
www.gettyimages.com/detail/news-photo/satellite-test-rock...
www.gettyimages.com/detail/news-photo/satellite-test-rock...
www.gettyimages.com/detail/news-photo/satellite-test-rock...
www.gettyimages.com/detail/news-photo/satellite-test-rock...
“VANGUARD TV-2: LAUNCH, 1957 Liftoff of the Vanguard TV-2 rocket from Cape Canaveral, Florida. Photograph, 23 October 1957.”
www.bridgemanimages.com/en/noartistknown/vanguard-tv-2-la...