E1

E1, E01, E.I or E-1 may refer to:

Transport

Trains and locomotives

Aircraft

Submarines

Roads

U.S. uniformed services pay grades

Pay grades are used by the uniformed services of the United States to determine wages and benefits based on the corresponding military rank of a member of the services. While different titles or ranks may be used among the seven uniformed services, pay grades are uniform and equivalent between the services and can be used to quickly determine seniority among a group of members from different services. They are also essential when determining a member's entitlements such as basic pay and allowances.

Pay grades are divided into three groups: enlisted (E), warrant officer (W), and officer (O). Enlisted pay grades begin at E-1 and finish at E-9; warrant officer pay grades begin at W-1 and finish at W-5; and officer pay grades begin at O-1 and finish at O-11. Not all of the uniformed services use all of the grades; for example, the Navy does not use the grade W-1, the Air Force discontinued use of the warrant grades in the 1960s, and both the Public Health Service and National Oceanic and Atmospheric Administration do not use any of the enlisted or warrant grades.

Rocketdyne E-1

Rocketdyne's E-1 was a liquid propellant rocket engine originally built as a backup design for the Titan I missile. While it was being developed, Heinz-Hermann Koelle at the Army Ballistic Missile Agency (ABMA) selected it as the primary engine for the rocket that would emerge as the Saturn I. In the end, the Titan went ahead with its primary engine, and the Saturn decided to use the lower-thrust H-1 in order to speed development. The E-1 project was cancelled in 1959, but Rocketdyne's success with the design gave NASA confidence in Rocketdyne's ability to deliver the much larger F-1, which powered the first stage of the Saturn V missions to the Moon.

History

Genesis

In July 1954 the Air Force Scientific Advisory Board's ICBM working group advised the Western Development Division (WDD) on their doubts about the Atlas missile that was then under development. Atlas used a number of unconventional features in order to meet its performance goals, and they felt that there was undue risk that if any of these proved unworkable in practice then the entire design would fail. The group suggested that a second ICBM project be started as a risk mitigation effort.

1 decametre

To help compare different orders of magnitude this page lists lengths between 10 metres and 100 metres.

Conversions

10 metres (very rarely termed a decametre which is abbreviated as dam) is equal to:

Human-defined scales and structures

Orders of magnitude (area)

This page is a progressive and labelled list of the SI area orders of magnitude, with certain examples appended to some list objects.

10^-70 to 10^-9 sqm

10^-8 to 10^-1 sqm

10⁰ to 10⁷ sqm

10⁸ to 10¹⁴ sqm

10¹⁵ to 10²⁶ sqm

10²⁷ and larger sqm

References

1 decimetre

To help compare different orders of magnitude this page lists lengths between 10 centimetres and 100 centimetres (10⁻¹ metre and 1 metre).

Distances shorter than 10 centimetres

Conversions

10 centimetres (abbreviated to 10 cm) is equal to:

Wavelengths

Human-defined scales and structures